May 20, 1952
269.3
COMMUNICATIONS TO THE EDITOR
oxygen bond. The strength of this interaction is a function of the aromatic substituent and of temperature, and ranges from a small amount of overlap of the orbitals to complete transference of the electron.
phenyltitanium triisopropylate were isolated, m.p. No decomposition occurred on storage 88-90'. under a nitrogen atmosphere a t 10'. However, the product decomposed rapidly when heated above its melting point. Analytical results are listed in Table I.
LABORATORY FOR INSULATION RESEARCH INSTITUTE OF TECHNOLOOY MASSACHUSETTS S. C. ABRAHAMS CAMBRIDGE 39, MASSACHUSETTS RECEIVED APRIL14, 1952
TABLE I ANALYSIS OF ORGANOTITANIUM DERIVATIVES Constituent
ISOLATION OF A COMPOUND CONTAINING T H E COVALENT TITANIUM-CARBON BOND
Sir:
e, 70
CsHsTi(OCsHr ) 8 Found Calcu(average) lated
Ti-Li complexa Found Calcu(average) lated
59.1 59.62 50.1 H, 70 9.2 8.63 8 . 9 Ti as TiOz, % 2 4 . 6 24.46 15.1 Halogen, % 0.23 (el) 15.2(Rr) 1-i, % Trace 2.5 CBHbTi( OC3H7)3.LiOCaH7.LiBr.(C*H&O.
49.95 8.13 15.12 15.11 ( R r ) 2.62
A study of the organic compounds of titanium has been carried out resulting in isolation of a compound containing the covalent titanium-carbon bond. Since titanium is a transition element with The reactions exhibited by phenyltitanium triisoits valence electrons divided between the third and fourth principal quantum groups, it cannot be propylate serve as a chemical proof of the presence expected to bear more than a superficial resem- of a titanium-carbon bond. An ether solution blance to other Group IV elements such as silicon, of the product gave a slowly developing organogermanium and tin which readily form stable co- metallic color test with Michler ketone; it oxivalent bonds with carbon. The consequent lack dized rapidly with oxygen to give a phenol derivaof stability and difficulty of formation of the tive; it reacted with water to give benzene, titantitanium-carbon bond is primarily responsible for ium hydrate and butanol; it reacted slowly with the repeated failures reported in the literature' diphenyl ketone to give triphenylcarbinol, and it failed to yield benzoic acid on treatment with since the first attempt by Cahours in 1861.2 Theoretical considerations which cannot be dis- "Dry Ice." These reactions are typical of an orcussed in this short space led us to the assumption ganometallic bond of low activity. The ether that relatively stable members of the class of com- solutions of the unisolated products obtained pounds of the type RnTi(CR')4-, might be pre- previously from phenylmagnesium bromide and the pared if n were 1 or, a t most, 2 and R were selected alkyl titanates exhibited similar reactions. The from the more electronegative organic groups. A titanium-carbon bond present in these compounds series of exploratory reactions between butyl was found to decompose spontaneously as follows CeH6:Tif +C6HI. + Tit3 titanate and various organomagnesium and organolithium reagents in 1: 1 to 4: 1 molar ratios sub- Free radical formation was shown by the ability stantiated this assumption and showed that the of the material to catalyze the polymerization of most stable carbon to metal bonds were formed with styrene. aromatic R groups. This work will be fully described in the JOURNAL The reaction between phenylmagnesium bromide a t a later date. and butyl titanate in a 1:1 molar ratio yielded a LEADCo., TITANIUM DIV. phenyltitanium derivative which was in too un- NATIONAL RESEARCH LABORATORIES DANIELF. HERMAN stable and reactive a state to be isolated from the SAYREVILLE, N. J. WALTERE;. NELSOS reaction mixture. When phenyllithium was used RECEIVED APRIL25, 1952 in place of the magnesium reagent, significant differences were observed leading toward the eventual isolation of phenyltitanium triisopropyl- CONFIGURATION AT C I ~OF 12-HYDROXYLATED ate in the following manner: The reaction of SAPOGENINS. REARRANGEMENT OF THE STEROID C/D RINGS pheriyllithium with isopropyl titanate in equimolar proportions led to the formation of a relatively Sir: insoluble crystalline, stable, lithium complex of Reduction of hecogenin with lithium aluminum phenyltitanium triisopropylate. Elementary an- hydride produced the Clz-epimeric diols: I, m.p. alysis and chemical properties indicated the follow- 216-220°, [ a ] " ~-32.4' (1.08, acetone). Found: ing formula : CCHETi (O C ~ H ~ ) ~ . L ~ O C ~(C2H~.L B ~ S H, 10.22; diacetate ( l a ) , m.p. 156-159', C,~75.40; [ a I z 3 -15' ~ (1.0, acetone). Found: C, 72.25; H&O. The lithium isopropylate portion of the molecule H, 9.34, and 11, m.p. 218.5-220.5', [ a I z 4-63.8' ~ reacted with titanium tetrachloride, as follows, to (1.05, acetone). Found: C, 74.79; H, 10.00; precipitate the lithium as the chloride, thus freeing diacetate (IIa), m.p. 202-206.5', [ a ] 2 3-65.1' ~ the organotitanium compound from the complex (1.0,acetone). Found: C, 71.88; H, 8.99. Molecular rotations of I, I1 and their respective diaceCaH&Ti( OCaH7)3.LiOCsH7.LiBr.(C*H&)zO+ */rTiCl, -----f tates compared with the Clz-epimeric cholanatesl CBHsTi(OCaH7)3 LiCl + LiBr + '/4Ti(OCaH,)4 + (GHE.)zO are in excellent agreement with the assigned con( 1 ) (a) B. Koechlin and T. Reichstein, Rels. Chim. A d a , 2S, 918 The lithium salts were filtered, and crystals of (1942): (b) E. Seebeck and T. Reichstein, i b i d . , 26, 536 (1943); (I
+
(1) H. Gilman and R. J. Jones, J . Org. Chcm., 10, 505 (1946). (2) M. A Cahours, A n n . chiwz, 131 63, 280 (1861).
T. F. Gallagher and W. P. Long, J . B i d Chcm., 162, 521 (1946); (d) D. H. R. Barton and W. Klyne, Chem b I n d . , 755 (1948).
COMMUNICATIONS TO THE EDITOR
2604
figurations a t Clz for I and 11. Confirmation of this configurational assignment was adduced by the markedly more rapid consumption of two equivalents of alkali by IIa in contrast to Ia. This is again in accord with the observed saponification rates for the corresponding Clz-epimeric acetoxy cholanates,’a and in conformity with the greater ease of hydrolysis associated with equatorial ester groupingsa2 Rockogenin3 isolated from natural sources was found to be identical with I1 and should, therefore, be assigned the 12( PS-0F-I configuration.
Vol. 74
having a single carbonyl band in the infrared a t 5.84 p and only end absorption in the ultraviolet. The formation of 111 from rockogenin by C/D ring contraction and expansion represents a rearrangement path wherein the stereoelectronic requirements are fulfilled only in the case of the natural Clz-p-configuration IL5 The significance of this geometrical factor is reflected in the extraordinary ease with which this rearrangement occurs.6 This C/D ring structural type has been advanced recently in the formulation of jervine’ and veratramine.* The present work constitutes the first chemical realization of this abnormal steroid system and affords thereby not only support for the C/D ring structures assigned to these alkaloids but also suggests a highly probable mode in their biogenesis. ’
(5) Compare the rearrangement-dehydration of 8- and r p i - 8 amyrin; cf. ref. 2. Also 0. Jeger “Fortschritte der chemie organischer Naturstoffe.” 1950, Vol. VII, p. 65. (6) Compare, for example, S . Winstein, B. K. Morse, E. Grunwald, €I. W. Jones, J. Corse, D. Trifan and H . Marshall, THISJOURNAL, 74, 1127 (1952). (7) J. Fried, 0.Wintersteiner, M. Moore, B. M. Iseiin and A. Klingsberg, ibid., 73, 2970 (1951). (8) Ch. Tamm and 0. Wintersteinu, Abstr. of the MeetinginMiniature of the Am. Chem. SOC., Newark, N. J,, Jan. 28, 1952.
MERCK8z Co., INC. RAHWAY, N. J.
RALPHHIRSCHMANN
C. STEWARD SNODDY, JR. K. I,. WENDLBR
RECEIVED MARCH 31, 1952 THE AMMONIA INDUCED DECOMPOSITION OF NITRIC OXIDE
1 1 1
R l O / W (111) Ri = CH3CO; Rz ( I V ) R1 H ; Rz = 0
CHP
Sir:
This is to report a serious flaw in the experimental technique of a recent investigation of the same title,’ I and I1 were converted by successive succinolyla- which invalidates its major conclusions. In that tion and treatment with methanesulfonyl chloride in work, the extent of the decomposition of NO was pyridine to: I b m.p. 185-188’ (dec.), [ a I z 5-13.4’ ~ determined by measuring the pressure of nitrogen (chf.). Found: C, 63.96; H, 8.50; SI 5.28, and in a previously evacuated bulb, partly immersed in Ilb, m.p. 127-132’ (dec.), [(rIz4~-48.4’ (chf.). liquid nitrogen and connected to the reaction vessel Found: C, 63.85; HI 8.45; S, 5.18, respectively. by capillary tubing. This procedure leads to Solvolysis of IIb in refluxing methanol or t-butanol entirely erroneous nitrogen pressures since nitrogen with or without added alkali alkoxide, produced an is enriched far above its correct partial pressure in olefin isolated as its acetate (111) m.p. 221-225’, the bulb when it is opened to the reaction vessel. [ a I z 3 D -80.6’ (chf.). Found: C, 76.21; H I 9.92, Mass flow will bring the gas mixture instantawith bands in the infrared a t 6.04 and 11.24 p . neously from the large reaction vessel into the bulb Under the same conditions of solvolysis Ib was where all condensable gases freeze out and leave a recovered essentially unchanged. nitrogen pressure much lower than that of the gas Hydroxylation of 111 with osmium tetroxide mixture remaining in the quartz vessel. The followed by saponification yielded a triol m.p., process therefore continues until the pressure of ca. 200°, converted quantitatively to a diacetate nitrogen in the bulb is equal to that of the gas m.p. 212-216’. Found: C, 70.30; HI 9.37, having mixture in the reaction vessel, still of its original an OH band in the infrared a t 2.8 p. Saponifica- composition, and therefore containing much nitric tion of this diacetate quantitatively regenerated the oxide. From then on, it is diffusion of NO into the triol, and the latter on cleavage with periodic acid bulb and diffusion of Nz back into the reaction produced 60-65y0 of formaldehyde, determined by vessel which would take the system to its final chromotropic acid titration4 and isolation of its state, but diffusion through capillary tubing is an dimedone derivative m.p. and m.m.p. with an exceedingly slow process. authentic sample 191’, together with a quantitaWe tested the correctness of this objection in tive yield of a no?-ketone (IV) m.p. 180-183°; various ways: A. By preparing known mixtures of [ a ] “ ~-93.8’ (chf.). Found: C, 75.01; H, 9.66, NO and Nz, following the procedure used in the reported note and obtaining measured ‘“2 pres(2) D. H. R. Barton, E.rpcricnlin, 6, 316 (1950). (3) Kindly supplied by Dr. L. A. Sweet of Parke, Davis & Co., sures’’ which were always much too high. B. Detroit, Michigan. By repeating some actual NO-NH3 experiments (4) C. E. Bricker and W. A. Vail, I n d . Eng. Chcm., A rol. Ed , I S , 720 (19.50).
(1) C. P. Fenimore and J. R. Kelso, THISJOURNAL, 74, 1593 (1952).
