The Stereochemistry of Raney Nickel Action. VI ... - ACS Publications

The Stereochemistry of Raney Nickel Action. VI. Functional Group Hydrogenolyses in the α-Substituted α-Phenylpropionic Acid Series. William A. Bonne...
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WILLIAMA. BONNERAND JOHN A. ZDERIC

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Vol. 78

Amax 2151° and 227 mp,I1 respectively, whereas cro- off the unreacted thionyl chloride, and adding the crude acid chloride carefully t o excess ammoniacal ether solution. tonic acid has Amax 208 mp.12 T h e amides were recrystallized from water or aqueous The absorption of a,$unsaturated nitriles (Table methanol. 11) is also very similar to that of the corresponding /3,/3'-Dimetliylacrylamide had m . p . 109' (lit. m.p. 110°16); acids. Braude13 reported that l-cyanocyclohex- tiglamide, m.p. 78' (lit. m.p. 77'17); cyclopentenylcarboxene had Amax 230 ( e 1,600) and 261 mp (E 60). amide, m.p. 204" (lit. m.p. 205°18e); cyclohexenylcarboxamide, m.p. 135' (lit. m.p. 136'180) and cycloheptenylcarThese values seem most unlikely for a simple chro- boxamide, m.p. 158' (lit. m.p. 157°18b). T h e ultraviolet mophore consisting of two unsaturated groups in light absorption determinations were carried out using conjugation. Frank, Berry and Shotwell'* re- freshly prepared solutions in 95yo ethanol, with a Beckman DU spectrophotometer. T h e alcohol was purified by disported that 1-cyano-4-isopropylcyclohexenehas tilling from zinc dust, and had good transmission t o 205 Xmax 212 (E 8,900) and 271 mp ( E 102). The first mp. T h e determinations were carried out in duplicate or maximum agrees with that found in the present triplicate, and no departure from Beer's law was observed. work for 1-cyanocyclohexene (I, n = 4,R = CX) T h e error in wave length was 4 ~ 5 0 0 . T h e results1gfor t h e acids are in better agreement with those of but a second maximum was not detected. The cy- cycloalkenyl Ungnade and Ortega*O than those of Braude and anoisopropylcyclohexene probably contained some co-workers. aromatics5 impurities, since i t was prepared by a Acknowledgment.-This work was supported by pyrolytic method. grants from the Rockefeller Foundation, New York. Experimental (1G) R . Kuhn, F. Kohler and L. Kohler, 2 . p h y s i o l . Chein., 247, 197

T h e samples of acids and nitriles were those prepared in part III.'b T h e acid amides were prepared b y heating the acids under reflux with excess thionyl chloride for 0.5 hours, distilling

(10) K . Bowden, E. A . Braude a n d E. R. H. Jones, J . Chem. Soc., 948 (1946). (SI) L. Crombie, i b i d . , 2997 (1952). (12) I. I. Rusob, J. R. Plate, H. B. Klevens a n d G. 0. Burr, THIS J O U R N A L , 67, 678 (1945). (13) E. A. Braude, A n n . R e g t . Chein. SOL.,42, 105 (1945). (14) R . L. Frank, R . E. Berry a n d 0. L. Shotwell, THISJOURNAL, 71, 3889 (1949). (15) Phenyl cyanide has Xmsx ca. 270 mp; G. Scheibe, Ber., 69, 2617 (1926).

[CONTRIBUTION FROM

THE

(1037). (17) H. Sutter, F. Rottmayrand and H. Porsch, A n n . , 621, 189 (1936). (18) (a) E. A . Braude and W. F. Forbes, J . Chem. Soc., 1755 (1951); (b) i b i d . , 2202 (1953); (c) E. A. Braude a n d J. A. Coles, i b i d . , 2014 (1950). (19) T h e discrepancy may be due t o t h e f a c t t h a t with t h e Hilger spectkophotometer t h e use of too large optical density intervals can give spurious "maxima"; E. A. Braude quoted by J. K. L. H. Allan, E. R. H. Jones and h f . C. Whithing, J . Chern. SOL.,1862 (1955). This cannot occur with photoelectric instruments, which were used by Ungnade and Ortega, and in t h e present work. (20) H. E. Ungnade a n d I. Ortega, THIS JOURNAL, 73, 1564 (1951).

MEXICO20, D.F.

DEPARTMENT O F CHEMISTRY AND CHEMICAL ENGINEERING O F STANFORD USIVERSITY]

The Stereochemistry of Raney Nickel Action. VI. Functional Group Hydrogenolyses in the a-Substituted a-Phenylpropionic Acid Series BY WILLIAMA. BONNERAND

JOHN

A. ZDERIC

RECEIVEDJANUARY 30, 1956 Optically active methyl and ethyl 2-phenyl-2-hydroxypropionates were dehydroxylated t o optically active 2-phenylpropionates b y action of Raney nickel in refluxing ethanol. The reaction occurred with predominant configurational retention, b u t with not quite a s high stereospecificity as previously suggested. Methyl D( +)-2-phenyl-2-methoxypropionate was demethoxylated under similar conditions t o methyl D( )-2-phenylpropionate, again with substantial retention of configuration. E t h y l ( +)-2-phenpl-2-aminopropionatefailed t o suffer deamination, b u t underwent reduction t o ethyl (+)-2-cyclohexyl-2-aminopropionate. Methyl 2-phenyl-2-formylaminopropionate failed t o undergo a n y reaction whatever, suggesting t h a t a free amino group is necessary for the observed facile ring reduction. 2-Chloro-2-phenylpropionamidewas smoothly cleaved t o 2-phenylpropionamide, providing a preliminary example of carbon-chlorine bond hydrogenolysis.

+

Previous investigations on the stereochemistry of Raney nickel catalyzed hydrogenolyses have indicated that phenylmercapt0,l benzenesulfinyl,2 benzenesulfonyl' and hydroxyl groups3 are removed from the a-position of the 2-phenylpropionamide skeleton by the hydrogen adsorbed on Raney nickel4 with varying stereochemical consequences. Thus the former two functional groups suffer hydrogenolysis with complete racemization of the 2-phenylpropionamide moiety, whereas the benzenesulfonyl and hydroxyl groups are removed with substantial retention of optical activity in the adjacent asymmetric center. LVhile the benzenesulfonyl group departs with apparent inversion of (1) W. (2) W. (3) W. (1952). (4) W.

A. Bonner, THISJOURNAL,74, 1034 (1952). A. Bonner, ibid., 74, 5089 (1952). A. Bonner, J. A. Zderic and G. A. Casaletto, i b i d . , 74, 5086 A. Bonner, i b i d . , 74, 1033 (1952).

the adjacent carbon atom, hydroxyl group removal results in retention of the starting configuration in the final product. In view of these divergent results it seemed pertinent to investigate other Raney nickel catalyzed functional group hydrogenolyses from, if possible, a stereochemical viewpoint. To this end we herein report new observations regarding hydrogenolyses of hydroxyl, alkoxyl, amino and chlorine functions by the action of excess Raney nickel in refluxing ethanol. It was previously stated3 that ethyl ~ ( - ) - 2 phenyl-2-hydro~ypropionate~ ( [f.2Iz5D-20.0°, 87% optically pure) was dehydroxylated to produce ethyl ~(+)-%phenylpropionate, [ c ~ ] ' ~ D 45.5' (ether), of over 90% optical purity, ;.e., with essentially no racemization. The latter figure was (5) K. Freudenberg, J. Todd and R. Seidler, A n n . , 601, 199 (1933); E. Eliel a n d J. Freeman, Tam JOURNAL, 74,923 (1952).

FUNCTIONAL GROUPHYDROGENOLYSIS IN PROPIONIC ACIDS

July 5, 1956

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estimated from the value, [a]D-51.0' (ether), reAttention was next turned to the stereochemistry ported for ethyl L( -)-2-phenylpropionate by Le- of Raney nickel catalyzed deaminations, since vene.6 Unfortunately, Levene's rotation is not Dahn has recently shown9 that certain substituted based on a completely resolved sample, as shown benzylamines undergo Raney nickel catalyzed reby the more recent report of Arcus and K e n y ~ n . ~placement of the a-amino group by hydrogen. TO From the latter study i t is possible to estimate a this end 2-phenyl-2-aminopropionicacid was prerotation of about 77" for optically pure ethyl paredlo and resolvedl1 through its formyl deriva~(+)-2-phenylpropionate, and to state that our tive by the procedure of McKenzie and Clough. previous product from the dehydroxylation of When ethyl (+)-2-phenyl-2-aminopropionate was ethyl D( -)-2-phenyl-2-hydroxypropionatewas ac- treated with Raney nickel in refluxing ethanol untually only about 7970 optically pure. Similarly, der the usual conditions, no deamination was obessentially completely resolved ethyl L ( +)-a- served. Instead, ring reduction occurred producphenyl-2-hydroxypropionate gave3 ethyl L( - ) -2- ing ethyl (+)-2-cyclohexyl-2-aminopropionate. phenylpropionate of 73T0 optical purity on treat- The latter compound was unambiguously characment with Raney nickel for three hours. This terized in the racemic series by its lithium aluproduct was reduced to 66% optical purity after minum hydride reduction to crystalline 2-cyd0further action of Raney nickel during 17 hours. hexyl-2-aminopropanol, followed by cleavage of The preparation of a sample of methyl D(+)-2- the latter with periodic acid to methyl cyclohexyl phenylpropionate of known optical purity now per- ketone and conversion of the ketone to solid derivmits us to report also that the dehydroxylation of atives. The facile reduction of ethyl 2-phenyl-2methyl D( - )-2-phenyl-2-hydroxypropionate oc- aminopropionate to the cyclohexyl derivative 67',, retention of optical configuration. finds some support in the work of Dahn,$ who recurred with 8 The varying extent of racemization noted during ports that Raney nickel tends to reduce benzylthe above reactions is a t present unexplained and amines, and contrasts to our earlier observations is under investigation. and those of Mozingo and co-workers12 who comExtension of our studies to hydrogenolytic de- ment upon the stability of aromatic rings under the alkoxylations gave stereochemical results qual- reaction conditions employed. It is interesting to itatively similar to those observed during dehydrox- contrast the present behavior of Raney nickel with ylation. D( -)-2-Phenyl-2-hydroxypropionic acid that of platinum catalyst, which failed to reduce was converted by repeated treatment with methyl ethyl 2-phenyl-2-aminopropionate during 48 hours iodide and silver oxide into methyl ~(+)-2-phenyl- a t 2.5' and 4 atmospheres hydrogen pressure. 2-methoxypropionate. Treatment of the latter Apparently the presence of a free amino group is with Raney nickel in refluxing ethanol produced a essential to facile reduction of the aromatic nucleus, sample of methyl D ( +)-2-phenylpropionate 72y0 since methyl 2-phenyl-2-formylaminopropionate optically pure. Demethoxylation was complete was recovered unchanged after treatment with after two hours reaction time, but appeared in com- Raney nickel under similar reaction conditions. plete after only 30 minutes, occuring with the same A preliminary study of carbon-chlorine bond stereochemical consequences as dehydroxylation, hydrogenolysis has been undertaken using racemic namely, predominant retention of configuration. 2-chloro-2-phenylpropionamide. Raney nickel unTo explain this retention mechanistically, one may der the usual conditions smoothly converts this postulate either a stereospecifically adsorbed car- substance into 2-phenylpropionamide, indicating bonium ion which abstracts a hydride ion from the that dechlorination of benzyl-type chlorides may catalyst surface from below its plane (l), or a occur under the same conditions as do desulfuraconcerted front side attack on the adsorbed tion, dehydroxylation and dealkoxylation. Stereochemical investigations of catalytic dechlorination R" are presently in progress, C-COOR"' Experimental -ROH /I R' 0-R Methyl 2-Phenyl-2-methoxypropionate.-The following ( R = H , CH3) preparation is a n adaptation of t h e method of Freudenberg.6 H H A mixture of methyl iodide (20 ml.), silver oxide (6.00 g.)

-

:

I

substrate by hydride ion. The racemization inherent in a free radical mechanism already has been discussed.

2-phenyl-2-hydroxypropionic acid (4.00 g.), Drierite ( 5 9.) and glass beads ( 5 g.) was stirred vigorously under reflux during 24 hours, whereupon i t was treated with anhydrous ether (20 ml.) and filtered. T h e filter cake was washed thrice with anhydrous ether, and the filtrate and washings were freed of solvent a t reduced pressure. T h e infrared spectrum of the residual oil was examined, then the oil was re-treated in the above manner four additional times. Only after the fifth treatment did the hydroxyl band a t 2.84 completely disappear. T h e final oil, light yellow in color, was distilled at 68-71' (1 mm.) t o give 3.43 g. (73%) of colorless product, n% 1.5029, d*0, 1.081. Anal. Calcd. for C I I H I ~ O ~C:, 68.02; H , 7.27; M R , 52.86. Found: C , 68.24, 68.39; H , 7.41, 7.52; M R , 53.04.

(6) P. A. Levene, L. A. Mikeska and K. Passoth, J . B i d . Chem., 8 8 , 27 (1930). (7) C. Arcus and J. Kenyan, J . Chem. Soc., 916 (1939). ( 8 ) H. Hauptmann and B. Wladislaw, THIS JOURNAL, 71, 707, 711 (1950).

(9) H. Dahn and U. Solms, Hclv. Chim. Acta, 36, 1162 (1952). (10) P. Levene and R. Steiger, J . Biol. Chem., 7 6 , 308 (1928). (11) A. McKenzie and G.Clough, J. Chem. Soc., 101,390 (1912). (12) R. Mozingo, C. Spencer and K. Folkers, THISJOURNAL, 66, 1859 (1944).

(Ni)

(Xi)

l S 8

WILLIAMA.BONNERAND JOHN A. ZDERIC

3220

Raney Nickel and Methyl 2-Phenyl-2-methoxypropionate. -One gram of the above ester and 6 g. of freshly prepared Raney nickella were heated in refluxing absolute ethanol (25 ml.) for a period of 25 minutes. T h e catalyst was filtered and rinsed with ethanol, and the solvent was removed at loo", last traces a t 1 nim. About 0.3 g. of clear oil was obtained, whose infrared spectrum was identical with t h a t of methyl 2-phenylpropionate. Methyl D( )-2-Phenyl-2-methoxypropionate .-This material was prepared from D( - )-2-phenyl-2-hydroxypropionic acid (m.p. 114', [ 0 l ] ~ ~ ~ - - 3 5(63.5, .4' abs. ether)) in thcnianner described above for the racemic modification. T h e final distilled oil had n Z o1.5023 ~ and [ c ~ j ~ ~ . ~ D(neat). 46.2~ T h e literature6 reports [ ( ~ ] 51.6" ~ o ~ (neat). ~ ~ On the basis of the acid used, t h e above material appears to be 97< optically pure. Raney Nickel and Methyl D( )-Z-Phenyl-Z-methoxypropionate.-The above optically active ester (1.42 9.) and Raney nickel (9 g.) were heated in refluxing ethanol (50 ml.) for two hours. Usual processing yielded 0.83 g. (69%) of oil, [ a I z 3 D 53.0" (c 5.5, ethanol), whose infrared spectrum coincided in all respects with that of methyl 2phenylpropionate. Tl'hen the reaction n-as duplicated during only a one-half hour reflux period, deniethoxylation appeared incomplete in t h a t several bands characteristic o€ the original methyl ether persisted in the infrared spectrum of the product. D( )-2-Phenylpropionic Acid and Derivatives.--2-Plicn~-lpropionic acid was resolved by the procedure of Arcus and Kenyon,' giving a dextrorotatory enantiomer having [ a I z 267.8" ~ (c 3.1, chloroform). Thesc workers report [ a ]74.8" ~ (chloroform), but fail t o record the temperature of measurement. Using their value as a maximum, the above resolved sample would be 96y0 optically pure. A portion of the resolved acid was converted7 t o D( +)-2phenylpropionamide, [ a I z 857.9" ~ ( c 1.6, chloroform), m.p. 100.5'. Arcus and Kenyon report [ a ]58.3" ~ (chloroform, temp. unspec.) and m . p . 96-97' for this amide, and state t h a t i t m a y be recrystallized to m.p. 103-104", giving no rotation for t h e higher melting sample. A sample of the above resolved acid \vas converted t o its inethyl ester b y action of diazomethane. T h e distilled reaction product had n 2 1 . 5 1.4978, ~ dZ92o 1.0409, [ r u I z 3 ~ 108.7' (c 5.5, ethanol), [ a I z g 92.4' ~ (neat). ( )-2-Phenyl-2-formylaminopropionic Acid .-2-Phenl-l2-aminopropionic acid was prepared from acetophenone, ammonium hydroxide and potassium cyanide by the method of Levene and Steiger,lo subl. p t . 269-271". After unsuccessful attempts to resolve this acid directly using ( -I)camphor-10-sulfonic acid, it was converted t o its formyl derivative and the 1-atterwas resolvcd using quinine after the procedure of McKenzie arid Clough." T h e resolved producl had m.p. 196-198' dec. and [ ~ x ] D87.0" c 3.3, etliariolj; reported" m.p. 194-195', [ a ] I 91.9" 6~ (c 3.2, Ctllallo~). Methyl ( )-2-Phenyl-2-formylaminopropionate .--Approximately 0.25 g. of diazomethane x i s prepared in ether (100 ml.). T h e solution was added slowly t o one of (+)-ephenyl-2-formylaminopropionic acid (1.OO g. ) in ethanol (15 ml.). T h e excess diazomethane was destroyed with a few drops of acetic acid, and the solvents were evaporated. T h e residue was recrystallized from a mixture of benzetje and ligroin, giving 0.91 g. of product, m . p . 109-110 . Further recrystallization gave a sample m.p. 113.5-115". Anal. Calcd. for CliH1303h-: C, 63.75; H, 6.32; S , 6.76. Found: C, 64.33, 64.37; H, 6.41, 6.50; S,6.99,

+

>

+

+

+

+

7.1 6 .

When a sample of this material was heated with Kaney nickel in refluxing ethanol in the usual way, during a 6-hour period, it was recovered unchanged. Several recrystallizations of the crude product from a benzeneligroin mixture gave platelets, m.p. 112-114', [ a 1 2 7 ~ , 2 5 . (3c02.4, acetone), whose infrared speetrum was identical with t h a t of the starting material. Ethyl (+)-2-phenyl-2-aminopropionate was prep;ircd b y hydrolysis and esterification of (+)-2-phenyI-2-formylaminopropionic acid after the procedure of hlcKenzie and Myles.14 T h e resulting ester had h.p. 69-70' (0.1 tnm.), nZaD1.5103, [ ( Y ] ' ~ D24.90 ( c 2.61, abs. ethanol), d 6 D 5.48' (neat, 1 0.5), in substantial agreement with the physical properties in the 1 i t e r a t ~ r e . I ~ (13) R.Mosingo.Org Synlhcses,Zl, 1 5 ( l ! l l l j ( 1 4 ) A . hlcgenzie and J. M y l e s . Bcr., 6 6 , 2 1 5 (1922)

Vol. 78

Raney Nickel on Ethyl ( +)-2-Phenyl-2-aminopropionate. -Two grams of the above ester, ca. 20 g. of Raney nickel and 50 ml. of absolute ethanol were heated under reflux for 5.25 hours. Customary processing gave 1.5 g. of colorlcss oil, b.p. 60-70" (0.5 mm.), n Z o1.4655. ~ This was found to be almost completely soluble in 5c& hydrochloric acid. T h e resulting acidic solution was extracted well with ether, made alkaline and re-extracted with ether. T h e latter extract vielded 1.07 g. of oil, b.p. 60-135' (0.5 mm.), [ c Y ] ~ ~18.66' D ( c 2.84, abs. ethanol), CPD 8.57 (neat, 1 0 . 5 ) . Iii contrast t o methyl 2-phenylpropionate, the product was completely transparent in the 240-270 xnfi ultraviolet spectral region. T h e sample w:is redistilled and a fraction, b.p. 60.5-61' (0.5 iiim.), i t Z 0 ~1.4639, taken for the analysis. T h e analytical data, as well as the observations below, indicate the product to be ethyl ( t)-Z-cycloliexyl-2-nminopro~~i(jnatc. .4nnl. Calcd. for C I I H l l O n S :C, iX.29; €1, 10.01'; S, 7.03. Found: C, 66.84, 66.89; H, 10.90, 10.72; S , 0.68, 6.75. 2-Cyclohexyl-2-a1nino-l-propanol,-I-lketone, characterized b>- similarity of its infrared spectrum to t h a t of an authentic sample, through its p-Ilitroplienylli?-drazone, 1n.p. 149-151" (recorded > d u e l 6 154"), and through its semicarbazouc, 111.p. after five recrystallizations from dilute ethanol 172-175', mixed m . p . with authentic sample (1n.p. 177'17) 173-177". 2-Chloro-2-phenylpropionamide.-2-Phenyl-2-l!ydrox)-propionic acid (30 9.) and thionyl chloride (50 ml.) were heated under reflux for three hours. T h e excess thionyl chloride was removed a t reduced preswrc nnd the resulting dark red residue was diitilled to give 11.9 g. ( 3 d r i ) o f ?-ellon-ish i d , 2-chloro-'7-piieiiripropioii\-l chloride, b .I). 58-60" (1 i n i n . ) . T h e still residuc was :I \7iscou\ tar. This nrocedurc is it niotiificatiim of thc nicthoti of 1fcKeiizie .rmmoiiia in methanol (140 i d . ) , and the solution v a s conceiitr,itcd a t ieduced prcssure t o tlircc-fourths of its original (15) A \-npel, " A l ' e x t b o o k nf Practical Organic C h e m i s t r y , " I.u!i;.mana, G r e e n anri Co., S c w Y m k , S . Y . , 1918, 1). 898. ( I f ; ) J . B r n i i n , H c r . , 4 0 , 3!)48 (l!ll)7). (17) U. \Vallach, A v ? ~ 389, ., 19%( 1 9 1 2 ~ .

July 5 , 1956

KADIOACTIVE CYCLOBUTANONE FROM KETENEAND DIAZOMETHANE-14C

volume. Water (100 ml.) was added, and the solution was chilled 12 hours, producing 6.1 g. (56%) of crude solid. This was recrystallized several times from a mlxture of benzene and ligroin, then vacuum sublimed (75-85" ( 1 mrn.)) t o produce pure 2-chloro-2-phenylpropionamide, m.p. 100-101". Anal. Calcd. for CgHloONC1: C , 58.84; H, 5.49. Found: C, 58.96, 59.12; H, 5.60,5.63.

[CONTRIBUTION

2080

FROM THE

3221

Raney Nickel and 2-Chloro-2-phenylpropionamide.-The above amide (0.57 9.) and Raney nickel (4 g . ) were heated for four hours in refluxing absolute ethanol (20 ml.). Customary work-up gave 0.20 g. (43%) of crude solid, m.p. 80-86". Recrystallization from benzene gave a sample, m.p. 88-93" undepressed on admixture with pure 2-phenylpropionamide. STANFORD, CALFORNIA

INSTITUTE OF CALIFORNIA O F CHEMISTRY, GATESAND CRELLINLABORATORIES TECHNOLOGY]

Small-Ring Compounds. XIV. Radioactive Cyclobutanone from Ketene and Dia~omethane-l~C' BY DOROTHY A. SEMENOW, EUGENE F. Cox AND

JOHN

D. ROBERTS

RECEIVED JANUARY 23, 1956 I t has been shown by the IC-tracer technique t h a t cyclobutanone is formed from the reaction I4C via a n intermediate possessing the symmetry properties of cyclopropanone.

OF ketene with diszomethane-

Introduction The formation of cyclobutanone from ketene and diazomethane a t - 70" was discovered by Lipp and Koster2in the course of research on possible syntheses of cyclopropanone. They formulated the reaction as proceeding v i a cyclopropanone as an inter(i)CH,CO

+ CH,N2

--*

N2 + P

O

mediate. I n support of this mechanism, i t was cited2that step 2 was similar to the path previously proposed for the formation of methyl ethyl ketone from acetone and diazomethane3 and that cyclic ketones such as cyclopentanone and cyclohexanone react with diazomethane to form higher homologs. Subsequent workers5 have questioned the cyclopropanone intermediate on the grounds that it was considered unlikely that cyclopropanone would react smoothly with diazomethane in ether a t -70" while cyclobutanone is stable under these same conditions. The present research involved the determination of the 14C-distribution in cyclobutanone prepared from ketene and diazomethane-14C in order to obtain direct experimental evidence bearing on the reaction mechanism. Synthetic and Degradative Procedures C y c l ~ b u t a n o n e - x - ~(I) ~ Cwas prepared from ketene and diazomethane-14C as described prev i o ~ s l y . The ~ ~ ~location of the I4C in the cyclobutanone (I) was achieved by 14C-analyses of the products of the following degradative scheme. Results and Discussion Inspection of the results of the I4C-analyses given in Table I reveals that the several ways of (1) Supported in p a r t by the Petroleum Research Fund of the American Chemical Society. (2) P. Lipp and R: Koster, Be?., 64,2823 (1931). (3) H.Meerwein and W. Burneleit, i b i d . , 61, 1840 (1928). (4) E. hlosettig and A . Burger, T H I S J O U R N A L , 62, 3456 (1930). ( 5 ) S. Yaarsemaker and J. Coops, Rcr. Irau. c k i v z . , 70. 1033 (1951).

EH3bH0 + ? k 3 d O 8 l 3

E

Y

NaOI

CHI3

m

adding and subtracting the various activities give agreement within the limits of error. Thus, the TABLE I RADIOACTIVITY ANALYSESOF DEGRADATION PRODUCTS OF cYCLOBUTASONE-X-14c

Meas. act.d Total act., Yo 3-Methyl-2-butanone ( I I ) a 0.1062 (100.00 =!= 0.43') Iodoform (111) ,02736 25.76 =!= . O l e Acetaldehyde (IV)b .06703 63.12 =k .06c Acetone (V)c ,03896 36.69 =I=.14" Iodoform (VI) .Ill956 18.42 i- .04e 3-Methyl-2-butanone as t h e 2,4-dinitrophenylhydrazone. Acetaldehyde as dimethone. Acetone as 2,4dinitrophenylhydrazone. Average activities in microcuries per millimole (wc./mmole); determined using the vibrating-reed electrometer method as described by 0. K . Neville, THIS JOURNAL, 70, ,1499 (1948). e Staridard deviation determined from three L I T more conibustiuns.