Slarch 20, 19%
O-TOLYL
'PHENYL R~IGRATION RATIOS
1409
was dried by azeotropic distillation and passed through an in 95% ethanol was measured with a model DU Beckman alumina column. Concentration of the benzene eluates spectrophotometer. Maxima and (log e) values are: afforded 17.7 g. (357,) of lO-carbethoxy-8-keto-5-methyl- 258 mp (4.57), 268 mp (4.63), 290 nip (4.55),302 mp (4.65), 1,Z,8,9,10,lOa-hexahydro-3,4-benzpyrene (XX) as a light 378 mp (4.38) and 398 mp (4.47). red oil which did not solidify. 5,8,10-Trimethyl-3,4-benzpyrene(XXV).-A mixture con5 , IO-Dimethyl-3 ,4-benzpyrene (XXII) .-A solution of taining 2.50 g. (0.0089 mole) of 8,10-dimethy1-3,4-benz17.7 g. (0.0493 mole) of 10-carbethoxy-8-keto-1,2,8,9,10,10a- pyrene (XXIII),'6 2.55 g. (0.019 mole) of S-methylformanhexahydro-3,4-benzpyrene ( X X ) , from above, in 100 ml. of ilide, 2.55 g. (0.017 mole) of phosphorus oxychloride and 10 anhydrous ether was added over a period of one hour a t ml. of o-dichlorobenzene mas warmed on a steam-bath for room temperature to 10 g. (0.26 mole) of lithium aluminum 2.0 hr. The resulting red solution was cooled, treated with a solution of 17 g. of sodium acetate in 75 ml. of water, and hydride suspended in 500 ml. of anhydrous ether. After refluxing for 2.75 hr. the reaction mixture was cooled and steam distilled. The residual brown solid, 8,lO-dimethyl3,4-benzpyrene-S-aldehyde (XXIV), was filtered, washed hydrolyzed with 357, sulfuric acid. Benzene was added and the organic layer was filtered, washed with water, and with water, and dried. T h e crude aldehyde was added to dried by azeotropic distillation. Concentration of the ben1.5 g. (0.054 mole) of 95% hydrazine, 2.0 g. of C.P. potaszene solution afforded 8-hydroxy-10-hydroxymethyl-5-meth- sium hydroxide and 25 ml. of diethylene glycol. The reyl- 1,2,8,9,10,1Oa-hexahydro-3,4-benzpyrene (XXI) as a sulting mixture was heated a t 100-115° for 30 min. and then a t 210-235' for an additional 90 min. The reaction viscous oil. mixture was allowed to cool and then was acidified with The crude diol S X I was directly dehydrated and dehydrodilute hydrochloric acid. The resulting brown precipitate genated by heating with 3.0 g. of 10Vo palladium-charcoal a t 285-355" for 1.25 hr. After cooling, the hard cake was was filtered, washed with water, and extracted with boiling dissolved in boiling benzene and the solution was chroma- benzene. The benzene solution was filtered, dried, and passed through an alumina column. Concentration of the tographed through alumina, and the material obtained by concentration of the benzene eluates was crystallized three benzene eluates yielded 0.67 g. (26%) of 5,8,10-trimethyltimes from ethyl acetate producing 2.85 g. of 5,lO-dimethyl- 3,4.-benzpyrene (XXV) as light yellow plates, m.p. 289-2915' 3,4-benzpyrene (XXII) as minute yellow plates, m.p. 227.5vac. An analytical sample, m.p. 290-292" vac., was pre230' vac. The material remaining in the mother liquors pared by crystallization from benzene. was purified zia the picrate providing an additional 0.80 g. Anal. Calcd. for C2%Hl5:C, 93.84; H , 6.16. Found: of X X I I , m.p. 228-230' vac., making the total yield 3.65 g. C, 93.92; H, 6.10. (26y0from X X ) . An analytical sample, m.p. 229.5-231' vac., was prepared by crystallization from ethyl acetate. Ultraviolet Absorption Spectrum.-The ultraviolet absorption spectrum of 5,8,10-trimethyl-3,4-benzpyrene (XXV) Anal. Calcd. for C, 94.25; H, 5 . 7 5 . Found: in 95co ethanol was measured with a model DU Beckman C, 93.73; H, 5.66. spectrophotometer. Maxima and (log e) values are: T h e hydrocarbon X X I I gave an unstable, purple picrate, 258 mp (4.61), 270 mp (4.63), 296 mp (4.58), 308 mp (4.73), m.p. 195-197'. Ultraviolet Absorption Spectrum.-The ultraviolet ab- 384 mp (4.42) and 404 mp (4.45). sorption spectrum of 5,10-dimethyl-3,4-benzpyrene( X X I I ) ALBCQCERQTE, NEW MEXICO
[CONTRIBUTION FROM THE CHEMISTRY D I V I S I O S O F O A K
RIDGENATIONAL
LABORATORY]
Molecular Rearrangements. XII. The 0-Tolyl/Phenyl Migration Ratios in the Pinacol Rearrangement ahd in the Deamination Reaction1 B Y VERNONF. RAAEN AND
CLAIR
J.
COLLINS
RECEIVED OCTOBER 23, 1957 T h e rearrangements, in cold, concentrated sulfuric acid, of diphenyl-o-tolylacetaldehyde(111) and the associated glycols
I and I1 have been studied by means of techniques similar t o those previously2 employed. The o-toIyl/phenyl migration
ratio has been estimated to be about 3. The a-tolyl/phenyl migration ratio in the deamination of 2,2-dipheny1-2-o-tolylethyl-l-C14-amine(VI) has been determined as 0.75. These results are explained, in the rearrangement of 111, on the bas.is of open carbonium ion intermediates whose life-times are long enough so that the various conformational isomers are in equilibrium; thus o-tolyl group mjgration predominates over phenyl because of a greater electrical effect and because more steric strain is relieved as a result of tolyl migration. In the deamination of lr1,however, it is postulated t h a t the open cationic intermediates are short-lived, do not reach equilibrium with respect t o their rotational isomers, and thus phenyl migration predominates over o-tolyl migration because conformations VI-1 and VI-2 are sterically more compatible than conformation VI-3.
Introduction and Results By an application of the same radiochemical techniques previously applied2t o the acid-catalyzed rearrangements of triphenylethylene glycol,2a and closely related trisubstituted glycols and aldehydes,2bwe have now studied the rearrangements in cold, concentrated sulfuric acid of compounds I, I1 and I11 t o the ketones IV and V. This series of compoundsYwas selected in order t h a t we might compare the o-tolyllphenyl migration ratio in the (1) This paper is based upon work performed a t Oak Ridge N a tional Laboratory which is operated for t h e Btomic Energy Commission by Union Carbide S u c l e a r Co. (2) ( a ) C. J. Collins, THIS JOURNAL, 77, 5517 (1955); (b) B. hl. Benjamin and C . J. Collins, ibid., 7 8 , 4329 (1956). (3) R. Roger and W. R. hlcKay. J . C h ~ mS. O L .332 , (1933).
aldehyde-ketone rearrangement of I11 with t h a t OH OH
I
Ph,C-C
1
OH OH
* H - c , ,
Ia
'
PhC-C
I
*HPh
erythro-lla
PhA*-& *HPh
threo-Ilab PhCHCOPh
PhzZdHO
I
FH? Ph2CHCO-m>
LJ
IIIab
OH OH
IV
1410
I'ERSON F. I
