3390
NEALE,SCHEPERS, AND WALSH
para isomer, and 11.05 p for the meta isomer.18 The deviation for the G-p ratio in the range of 0.4 to 2.0 was 0.05 (2 q), while the deviation for the meta isomer content in the O-lOyo range was 0.3 (2 u ) . For these analyses the samples were distilled to remove small amounts of the dinitrotoluene isomers, which interfered with the determination. I n general, dinitration was negligible. Some of the analyses were also determined by a V.P.C. methodlg using a 12-ft. Apiezon L grease column. General Procedure for Nitration.-In the general procedure the nitrating reagent was added slowly with stirring to the toluene which was either dissolved in a solvent or mixed with an acid, under anhydrous conditions. The reaction mixture was stirred for the indicated periods, drowned in ice-water, and extracted four to five times with chloroform. The combined chloroform extracts were washed with a dilute sodium carbonate solution, dried over anhydrous magnesium sulfate or sodium sulfate, and distilled to remove the solvent. When the analysis utilized the V.P.C. method, the pot residue was used directly and without further treatment; when the analysis utilized the infrared spectral procedure, the pot residue was fractionated to obtain the isolated mononitrated products, boiling a t 96' a t 10 mm. Nitration of Toluene with Neopentyl Nitrate in Polyphosphoric Acid.-To a mixture of 55.3 g. of toluene and 71.0 g. of poly(18) F. Pristera and M. Halik [Anal. Chem., 97, 217 (1955)l determined the meta isomer using the 12.49-p absorption band, but this is interfered with by the equally strong 12.7-p band of the ortho isomer. (19) J. S. Parsons, S. M. Tsang, M. P. DiGiaimo. R. Feinland, and R. A . L. Paylor, ibid., 88, 1858 (1961).
VQL. 29
phosphoric acid in a 250-ml., three-necked, round-bottomed flask fitted with a stirrer, thermometer, and dropping funnel was added 20.0 g. of neopentyl nitrate over 3 hr. and 38 min. During the addition the temperature ranged from 30 to 31.5", and a t the end of the addition the reaction mixture was allowed to stir overnight a t 30". Finally, the reaction mixture was heated to 40" and stirred a t 40" for 1 hr. Infrared absorption spectra of both the polyphosphoric acid and toluene layers showed the presence of nitrotoluenes and the absence of neopentyl nitrate by the failure to observe a band a t 13.2 p . The reaction mixture was then drowned in 300 g. of ice-water and extracted with chloroform. The combined chloroform extracts were washed with 50 ml. of 594 sodium bicarbonate solution and water and dried over anhydrous sodium sulfate. The solvent was removed by distillation until the pot temperature reached 130", and the residue was distilled to give two fractions: (a) 12.94 g. boiling a t 8489" a t 10 mm., and (b) 14.74 g. boiling a t 94-102" a t 8-10 mm. Analysis showed fraction a to contain 5.16g. of mononitrotoluenes and fraction b to be all mononitrotoluenes; total yield of mononitrotoluenes was 19.90 g. (97y0), having an 0-p ratio of 0.49, determined by infrared absorption data.
Acknowledgment.-We are indebted to Professor H. C. Brown for helpful discussions, to Dr. J. L. Gove for the infrared spectral analyses, to Dr. R. L. Anister for the Raman spectral data, and to Miss I. H. Prokul for the microanalyses.
The Chlorination of Reactive Anilines R. S. NEALE,R. G. SCHEPERS, .4ND 31. R. WALSH Unzon Carbade Research Institute, Tarrytown, New York Received June 15, 1964 Chlorination of aniline and N-alkylanilines with N-chlorosuccinimide in hot benzene afforded 65-95y0 of mixtures of o- and p-chloroanilines. Very little tar or dichlorinated material was produced, and the 0-p ratio usually exceeded 2, even in the case of N-t-butylaniline. The products appear to arise mainly from a facile rearrangement of intermediate N-chloro isomers.
As a result of our studying the chemistry of aminium radicals >N+,we wished to prepare some representative alkylaryl-K-chloraniines, ArN(Cl)R, a class of compounds not represented in the literature. Treatment of various anilines with N-chlorosuccinimide (NCS) in hot benzene, however, yielded only mixtures of mono-o- and -p-chloroanilines in 65-95% yield (Table I), instead of the desired N-chloro isomers. This reaction therefore affords a convenient method for the direct monochlorination of reactive anilines under mild conditions without the use and subsequent removal of protecting groups. These mild conditions may also be generally suitable for the monochlorination of other reactive aromatic compounds, if specific effects due to the presence of the nitrogen atom in the anilines studied are not important to the prevention of polychlorination. The 0-p ratio of the product mixture was high, usually greater than 2 : 1, and could be increased t o some extent by employing an excess of the aniline relative to NCS. The method is therefore particularly suited to the preparation of o-chloroanilines, which may be obtained free of the para isomers by simple fractional distillation. I n the only previous report of synthetically useful procedures for the chlorination of anilines, which was limited to N,N-dimethylaniline, the 0 - p ratio and yield were shown to depend heavily on the chlorination system; our study not only (1) T. H. Chao and L. P. Cipriani, J. Org. Chem., 96, 1079 (1961).
discloses the generality of chlorination by XCS in an inert solvent, but provides strong circumstantial evidence for the formation of the desired N-chloroanilines as intermediates in these reactions. Discussion The results presented in Table I favor a chlorination mechanism whereby at least a niajor part of the reactions proceeds through N-chloro intermediates. The 0-p ratio observed in most cases slightly exceeded the statistically possible 2 : 1 distribution, and decisively exceeded the 1.8 (or less) to 1 distribution normally expected from electrophilic substitution by a very small, reactive species such as YO2+ or Clz in a polar ~ o l v e n t . ~The high 0-p ratios appear to support an intramolecular rearrangement of intermediate X-chloroanilines to ring-chlorinated products, for the following reasons. By analogy to the direct electrophilic chlorination of toluene3 one might predict for the possibility of uncatalyzed chlorination by free chlorine, formed in situ, maximum 0-p ratios on the order of 1.5 in hydroxylic solvents, but ratios considerably less than unity in a nonhydroxylic solvent. The 0-p ratios obtained now in benzene obviously contrast markedly with this; this suggests that free chlorine is not the (2) R. Ketcham, R. Cavestri, and D. Jambotkar, zbzd., 98, 2139 (1963). (3) L. M. Stock and .4.Himoe, Tetrahedron Lettere. No. 18, 9 (1960).
KOVEMBER, 1964
CHLORINATION OF REACTIVE ANILINES
TABLEI CHLORINATION O F ANILINES,' C&NRiR2, WITH N-CHLOROSUCCINIMIDE I N REFLUXING BENZENE Entry
RI
Rz
1 2 3 4 5 6 7
H H H H CH3 H H
H CH3 n-CaHg t-CaHg CH3 CH3d t-C4Hgd
Reaction time, min.*
40 70 -60 100 180 e
135
o-Cl/p-C1 2.4 2.2 2.3" 1.85 1.8 3.4 2.3
% yield o
+p
65 73 85 95 85 79 78
H t-CaHg 29 H CH311 1.85 99 CH3 CH3\ 55 1.35 10% excess aniline; experiments not duplicated. * Determined by testing for presence of NCS with acidified potassium iodide solution; reflux temperature attained in 15 min., not included in times listed. c N-chloroacetanilide used as chlorinating agent. 2007, excess aniline. e Overnight a t room temperature. f Equimolar mixtures of NCS and each amine.
chlorinating agent if there is no unusual coniplexing effect due to the nitrogen atom. Because NCS is a relatively large reagent, one should expect that direct electrophilic chlorination by NCS would give lower 0-p ratios than 1.8, arid that intermolecular chlorination by an N-chloroaniline, a chloroanilinium salt I, or a chlorine-aromatic complex would also lead to low 0-p ratios due to the spacial requirements of all these reagents. However, even in the case of N-t-butylaniline the ratio 1.8:1 was observed (eq. l ) , which could be raised to 2.3 (Table I, entries 4 and 7), although the expected ratio allowing for steric shielding of one ortho position would be unity. Furtherniore, N,N-dimethylaniline (entry 5 ) underwent considerably more para attack than aniline or N-niethylaniline and reacted more slowly than N-t-butylaniline; this implies that the presence of an S - H group facilitated ortho chlorination in some way and argues against a process involving a simple complex of the chlorinating agent with the anilines, since such a complex is not ruled out by the nature of the substituents on the aniline nitrogen atom. Formation and rearrangement of X-chloro intermediates therefore emerges as the most reasonable path to the production a t least of the ortho-chlorinated products. t-C,Hg--NH
h
v
+ o
c*
k
kC4H9-NH
benzene
t-C,Hs -NH ,c1
reflux 100 min.
o
YY
62 %
,-..I 35%
U
The data do indicate, however, the occurrence of a second mode of ring chlorination in competition with that via N-chlorination. A comparison of entry 2 with 6 and of entry 4 with 7 reveals that the 0-p ratio may be increased by iiiaititaining a large excess of the aniline relative to NCS. This is reasonable if a certain amount of electrophilic attack on the ring occurs directly a t the para position at a rate different from that of N-chlo-
3391
rination and rearrangement. Whether such an attack involves NCS, the S-chloroaniline, or even the salt I, is a moot point. The degree to which such an alternative chlorination path might operate was considered next, although the relatively small increase in the 0-p ratio when the aniline was present in large excess suggests a proportionately small participation of direct attack on the ring. To test whether the majority of para-chlorination appeared to occur through direct attack or from rearrangement of an S-chloro intermediate, a competition experiment (entry 8) was carried out between Nt-butyl- and N-niethylaniline. An estimate of steric interference to coplanarity of the -KR2 group with the ring in aniline derivatives is afforded by their ultraviolet spectra4; since the spectrum of N-t-butylaniline [A?:",""" 237, 292 mp (emax 6400, 820)] indicated only a moderate steric effect of this type compared with Nmethylaniline 243,295 nip (emax 13,200, 2300)], it was thought that deactivation of the ring to direct electrophilic attack in N-+-butylaniline might not be nearly so important as steric inhibition to i\;-chlorination by NCS. However, some ring deactivation had to be expected on the basis of the enhanced pKa of S-tbutylaniline (7.1) relative to the usual range 4.5-5.1 for N-alkylanilines,5 and this increased basicity, aside from steric effects, could render S-2-butylaniline more susceptible to N-chlorination than the other anilines. Nevertheless, two different mechanisms ( i e . , E-chloro rearrangement and direct para attack on the ring) should not be equally sensitive (except fortuitously) to the change of the alkyl group on nitrogeii from methyl to t-butyl, whatever the effect this change might have on ring deactivation and the basicity of the nitrogen atom. The relative amount of ortho us. para chlorination of the two conipounds was therefore expected to be rather unequal if both mechanisms were important, although the S-methyl compound might undergo more rapid reaction The similar 0-p ratios actually observed in the chlorination of the two anilines with a limited amount of KCS, therefore, suggest that under the competition conditions both para and ortho chlorination resulted mainly from rearrangenlent of N-chloro intermediates and that variations in the 0-p ratio under other reaction conditions reflected the presence or absence of relatively small amounts of direct para attack on the ring, A competitive reaction between S-methylaniline and K,S-dimethylaniline was then carried out, Nom the 0-p ratio of the chlorodiiiiethylanilines was expected to remain lower than that of the chloromononiethylanilines, since it was thought that dimethylaniline would react mainly via some direct electrophilic substitution process and would thus be unaffected except in rate by a change in concentration of the reactants. The result (entry 9) shows that the presence of monomethylaniline deweased the 0-p ratio of the dimethylaniline products, in contrast to its effect in the competition with t-butylariiline. However, the 0-p ratio of the morioiiiethylanilirie products was also lower than in the noncompetitive reaction (entry 2) , arid the dimethyl compound was now the more reactive substrate in (4) H. H. Jaff6 and M. Orchin, "Theory and Applications of Ultraviolet Spectroscopy," J o h n Wiley and Sons, Inc., S e a York. N. Y . , 1962, p. 410. ( 5 ) G . Vexlearschi and P. Rurnpf, Compt. rend., 229, 1152 (1949).
3392
NEALE, SCHEPERS, AND WALSH
VOL.29
TABLE I1 PHYSICAL CONSTANTS OF ANILINESAND CHLORINATED ANILINES -bsd. B.p., OC. (mm.)*
Compd.
7
?LD,deg.
(temp.)
B.P. (m.p.), OC. 208.8 (70-72)d 218 239-240' 206" 231 (35)' Q
Lit.--O-
nn
o-Chloroaniline 99(19) 1.5862 (25) 1 . 5895c (20) p-Chloroaniline 120 (19) ... o-Chloro-N-methylaniline 106 (20) 1.5780 (25) 1,5780' (25) p-Chloro-N-methylaniline 120 (20) 1 ,5799 (25) ... 0-C hloro-N,N-dimethylaniline 102 (21) 1.5510(24) , . . p-Chloro-N,N-dimethylaniline 127.5 (21) ... ... o-Chloro-N-n-butylaniline 8 1 . 5( 0 . 9 ) 1.5404 (25) . p-Chloro-N-n-butylaniline 74-77 (0.06) 1 ,5478 (24) h ... h'-t-Butylaniline 97 (19) 1.5246 (24) i ... ... o-Chloro-N-t-butylaniline 1 1.5346 (24) j p-Chloro-X-t-butylaniline 1 1.5416 (24) k ... Elemental analysis given for new compounds. Uncorrected. F. D. Chattaway and K. J. P. Orton, J. Chem. Soc., 79, 462 N. V. Sidgwick and H. E. Rubie, ibid., 119, 1013 (1921). e B. Helferich and H. Stetter, Ann., 557, 237 (1947). ( 1901). J. H. Gorvin, J . Chem. SOC.,1237 (1953). * Anal. Calcd.: C, 65.39; H, 7.68; N, 7.63; C1, 19.30. Found: C, 67.01; H, 8.12; N, 7.38; C1, 18.23. Found: C, 64.45; H, 7.44; N, 7.55. * See ref. 10. Found: C, 65.52; H, 7.92; N, 8.01; C1, 19.35. Found: C, 65.82; H, 7.86; N, 8.50; C1, 18.10. Not distilled; isolated pure by g.1.c. I . .
'
contrast to the relative reaction times recorded in entries 2 and 5. A detailed explanation of these effects is not possible from the data in Table I. However, it is evident that dimethylaniline is the only compound in the series which lacks a labile K-H bond and is thereby prevented from forming a neutral N-chloro derivative (11, eq. 2). This aniline reacted differently from the others and appeared to introduce a new mode of reaction into the chlorination of methylaniline during the competition, as judged from the increased amount of para attack evident in both substrates relative to that of either aniline alone. We believe this is due to the inability of dimethylaniline to form a free K-chloro derivative I1 (eq. a),which results in the reaction of this aniline by other paths which can affect conipeting N-H type substrates and may in part depend on their presence. One such path may involve a salt I when I cannot form I1 by proton loss.6
I CeHhNR2
+ NS-Rl
(2)
A1 I1 when RI = H
Experimental Chlorination of N-Substituted Anilines.-In a typical experiment, 0.033 mole of N-t-butylaniline and 0.03 mole of recrystallized NCS were heated under reflux for 100 min. in 150 ml. of benzene. The benzene solution, cooled t o precipitate succinimide, was filtered and evaporated under vacuum. The residue was steam distilled from 6 N sodium hydroxide solution to afford 6270 of o-chloro-N-t-butylaniline and 35% of p-chloro-Y-t-butylaniline, based on 0.03 mole of NCS. In some cases, a very small amount of the 2,4-dichloroaniline appeared to be present in the steam distillation residues. The o-chloro isomer showed n.m.r. absorption at T 8.63 (singlet, 9H, t-butyl), at 5.82 (singlet, l H , K-H), and at 2.7-3.6 (asymmetric multiplet, 4H, aromatic hydrogens). The p-chloro isomer absorbed a t T 8.70 (singlet, 9H, t-butyl), at 6.68 (singlet, lH, N-H), and at 3.22 (symmetri(6) One might speculate upon the anomalies accruing to the competition reaction involving dimethylaniline in terms of intermolecular reactions of species I or I1 which compete with reactions of NCS and with intramolecular rearrangements of 11. but considerably more data are required to make such an exercise useful.
cal multiplet, 4H, aromatic hydrogens). All the products, is0 lated and identified as described below, were characterized according to the properties recorded in Table 11. The reaction products were isolated, most in ultrapure form, by gas chromatography7 and identified from their infrared and n.m.r. spectra. The o-chloro isomers absorbed at 751-740 cm.-l in the infrared* and afforded n.m.r. spectra containing an unsymmetrical multiplet due to the aromatic hydrogens; the p-chloro isomers absorbeds at 819-810 cm.-l and produced symmetrical aromatic hydrogen n.m.r. patterns. Per cent yields of each product were then calculated from g.1.c. analysis of the reaction mixtures using the previously isolated pure compounds as standards. We were surprised to observe that the N-CH, peak of o-chloroN-methylaniline appeared as a clean doublet (singlet in trifluoroacetic acid); the rather slow N-H exchange rate in this compound required to permit observation of the H-N-CHI coupling8 was probably a result of hydrogen bonding of the N-H to the ochlorine atom. o-Chloro-N-n-butylaniline showed a similar effect. N-t-Butylaniline .-The N-t-butylaniline actually used was prepared for another purpose as described previously.1° We attempted, with only partial success, to prepare the compound by the methylation of acetone anil with methyllithium. Unfortunately, allylic hydrogen abstraction always competed with addition to the K=C bond, resulting in a mixture of the desired product with the anil on work-up. Enolization was the only reaction when anils were treated with methyl Grignard or sodium hydride.ll In the best run, 360 ml. of 1.3 M methyllithium in ether (Lithium Corporation of America) was stirred rapidly in 250 ml. of anhydrous tetrahydrofuran while 6 g. of acetone anil in 20 ml. of the same solvent was added slowly. The mixture was heated under reflux for 6 hr. after distilling off the ether, and was then cooled and decomposed with 200 ml. of water. The organic layer was washed with water, dried, and stripped to 6.7 g. of residue which was shown by g.1.c. analysis to contain 2.2 g. of anil, 4.1 g. of N-t-butylaniline, and 0.4 g. of aniline; the latter product was probably produced by hydrolysis of the anil during work-up. The yield of N-t-butylaniline was 617, (94% based on unrecovered anil). Retreatment of the mixture initially obtained with methyllithium would no doubt greatly increase the yield. The method therefore appears worthy of consideration for the general preparation of N-t-alkylanilines of the type CeHhNCRiRzRz.
(7) G.1.c. analyses and collections were obtained with a 15 ft. X 3/a in. aluminum column packed with Csrbowax 6000 on Fluoropak. ( 8 ) L. J. Bellamy, "The Infrared Spectra of Complex Molecules," 2nd Ed., John Wiley and Sons. Inc., New York, N. Y., 1958, p. 65. (9) L. M. Jackman, "Applications of Nuclear Magnetic Resonance Spectroscopy in Organic Chemistry," Pergamon Press, Inc., New York, N. Y . , 1959, p. 28. (10) W.J. Hickinbottom, J . Chem. Soc., 946 (1933); the sample used was kindly provided by Dr. G. R. Evanega. (11) G. Stork and S. R. Dowd, J . A m . Chem. Soc., 86, 2178 (1963).
XOVEMBER, 1964
czs-fl-DIcALoLs AND cis-p-DECALYLAMINES
Acetone Anil. Method A.12-Phenylammonium iodide (22.1 g.) and 47 g. of silver iodide were dissolved in 75 ml. of hot dimethylformamide, and 250 ml. of acetone was added. The solution was heated until the yellow color disappeared, then cooled to deposit white crystals which were collected and decomposed with a solution of 33 g. of potassium cyanide in 50 ml. of 2070 potltssium hydroxide. Extraction with ether gave 8.7 g. of crude acetone anil ( 6 5 % ) . (12) R. Kuhn and H. Schretzmann, Aneew. Chem., 67, 785 (1955).
3393
Method B.-The second method of preparation of acetone anil involved condensing aniline and acetone in the presence of a drying agent.la In the best run, 10 g. of aniline and 100 ml. of acetone were boiled in a Soxhlet extractor containing a thimble filled with potassium carbonate mixed with calcium sulfate to prevent lumping. After 23 hr., about two-thirds of the aniline had been converted to the anil according to g.1.c. analysis. The product could be isolated by careful fractional distillation. (13) C. C. Tung, Tetrahedron, 19, 1685 (1963).
The Configurational Relationships of the cis-p-Decalols and cis-fi-Decalylamines' THEODORE COHEN,A!!. MALAIYANDI, AXD JACK L. PIXKUS Department of Chemistry, Universzty of Pittsburgh, Pittsburgh, Pennsylvania Received J u n e 66,1964 The question of the configurational relationships of the cis-p-decalols and cis-p-decalylamines has been un,ambiguously resolved by examining the products of ammonolysis of the tosylates of both alcohols. Cleanly inverted amines are obtained. The assignments of Dauben and Hoerger are shown to be correct. The suitability of the ammonolysis method for such configurational correlations is pointed out.
I n recent years, there has been a great deal of interest shown in the stereochemistry of nitrous acid deaminations in cyclic systems.2-8 In, order to interpret the experimental data, it is usually necessary to know the configurational relationship between the epimeric pair of amines and the corresponding epimeric pair of alcohols. A classical method often usedg~'Oto establish this relationship involves the expectation that the ratio of epimeric alcohols obtained by a given method of reduction of a cyclic ketone will be similar to the ratio of epimeric amines obtained upon similar reduction of the oxime of the ketone. It is then assumed that the predominant components of the two epimeric pairs are configurationally related. Upon application of this method to the cis-p-decalols and cis-p-decalylamines, HUckelgfound that hydrogenation of cis-fl-decalone and its oxime, over a colloidal suspension of platinum in a solution of aqueous acetic acid containing hydrochloric acid, yielded rather homogeneous samples of an alcohol, m.p. 105', and an amine (melting point of acetyl derivative 153'; melting point of benzoyl derivative 204") , respectively. The same two compounds predominated in the epimeric alcohol and amine mixtures when the ketone and oxime were reduced with sodium and alcohol. This alcohol and amine were thus assigned the same configuration, while the epimeric configuration was assigned to the minor components of the alkali reduction mixtures, an alcohol having a double melting point of 18 and 31' and an (1) This work was supported b y Grant B-19 from the Health Research and Services Foundation, Pittsburgh, Pa. (2) (a) A. K. Bose, Ezperientia, 9, 256 (1953); (b) J. A. Mills, J. Chem. Soc., 260 (1953). (3) C. W. Shoppee, D. E. Evans, and G. H. R. Summers, ibid., 97 (1957); C. W. Shoppee, R. J. W. Cremlyn, D. E. Evans. and G. H. R. Summers, ibid., 4364 (1957). (4) W. G. Dauben, R. C. Tweit, and C. Mannerskantz, J . Am. Chem. Soc., 76, 4420 (1954). (5) A. Streitwieser, Jr., and C. E. Coverdale, ibid., 81,4275 (1959). (6) G.Drefahl and S. Huneck, Be?., DS, 1961, 1967 (1960). (7) W. Hiickel and K. Heyder, ibid., 96, 220 (1963). (8) T. Cohen and E. Jankowski. Abstracts of Papers, 147th National Meeting of the American Chemical Society, Philadelphia, Pa., April, 1964, p. 47N. (9) W. Hiickel, Ann., 633,1 (1938). (10) W. HUckel and G. Stelzer, Ber., 88, 984 (1955).
amine, the acetyl derivative of which melts a t 88' and the benzoyl derivative a t 128'. Because these assignments did not lead to a consistent picture of the stereochemistry of the nitrous acid deamination of decalylamines, they were reinvestigated by Dauben and Hoerger. l 1 These authors converted each of the cis-decalin-2-carboxylic acids to an alcohol by treatment with methyllithiuni followed by peracid oxidation and hydrolysis, and also to an amine by treatment of each acid with hydrazoic acid. These reactions are considered to be stereospecific, involving retention of configuration. As a result of this study, the original stereochemical assignmentsg were reversed. Dauben and Hoerger assigned the same configuration to the alcohol, m.p. 105' and acetamide, m.p. 88'. Four years later, Huckel and Stelzer'O reported a reinvestigation of this question. They repeated some of the earlierg reductions using improved analytical procedures and they carried out several reductions under new sets of conditions. In all cases the newer results supported the original assignmentsg and therefore appeared to contradict the assignments of Dauben and Hoerger.11
cGx mX
X X
= =
X X
= =
Dauben Assignment OH, m.p. 105" X = OH, m. . 18 and 31" NHCOCH,, m.p. 88" X = NHCO8H3, m.p. 153" Huckel Assignment OH, m. . 105" X = OH, m.p. 18 and 31" NHCOEH3, m.p. 153" X = NHCOCH,, m.p. 88"
We now wish to report the results of experiments which establish the configurational relationships between the cis-@-decalolsand the cis-@-decalylaminesby a more direct means than the previous methods. The procedure is related in principle to those originally used12 to establish stereochemical relationships in acyclic systems. It consists of converting each alcohol to its p-toluenesulfonate ester and converting the latter to (11) W. G.Dauben and E. Hoerger, J. Am. Chem. S o c . , 73, 1504 (1951). (12) A. J. H. Houssa, J. Kenyon, and H. Phillips, J. Chem. SOC., 1700 (1929).
