1216
*kNDRE
s. DREIDINGAND JOHN
electrophilic nature of the permanganate oxygen and the electron donor character of the c5arged oxygen atom of the formate. This mechanism is in a sense analogous to the mechanism proposed by Denneys for the rearrangement of 9-decalyl hydroperoxide benzoate. Since approximately one-half of the oxygen introduced into the formate came from the permanganate, mechanism E may be considered, in which one of the oxygens of the formate and one from the permanganate become equivalent in the intermediate. Cleavage of the intermediate would then (8) D. B. Denney, THISJ O U R N A L , 7 7 , 1706 (1955).
[CONTRIBUTION FROM THE ROLLIX
H.
A. HARTMAN
Vol. 78
lead to carbon dioxide in which one oxygen would have one-half the 0l8content of the permanganate. An equivalent result would be obtained if the intermediate in mechanism C would permit an exchange of the blnOa group from one oxygen to the other. It unfortunately does not appear possible to obtain direct evidence concerning these possible mechanisms at the present time.
SEATTLE, bVASHINCTON
STEVENS MEMORIAL LABORATORY O F THE
DETROIT INSTITUTE
O F CANCER RESEARCH]
The Rearrangement of Some Substituted Allyl Alcohols to their Isomeric Ketones' BY ANDRES. DREIDING AND
JOHN
A. HART MAN^
RECEIVED JUNE 28, 1955 The allylic pair 2-methylenecyclohexanol and 1-cyclohexenemethanol rearrange to the isomeric 2-methylcyclohexanone in the presence of sulfuric acid. Similar results are obtained in the homologous five-membered ring series.
It has been shown that the enolic forms of some 8-dicarbonyl compounds are reduced by an excess of lithium aluminum hydride to give one or a pair of substituted allyl alcohols, the number being dependent on the symmetry of P-dicarbonyl c o m p o ~ n d . ~ A pair of allyl alcohols obtained by such a procedure is usually characterized by their susceptibility to the acid-catalyzed oxotropic rearrangement which results in the more stable isomer. However, complete conversion is often not realized in the absence of some stabilizing factor such as conjugation and, a t elevated temperatures, etherification and/or dehydration may compete with rearrangement. The isolation of the 2-methylenecycloalkanols (I) (x = 1 and 2 ) and the 1-cycloalkenemethanols (11) (x = 1 and 2) has furnished two p i r s of isomeric allyl alcohols LThich should be capible of u.1dergoing at least a partial rearraiigemmt on treatment with a c d 3 -1 projection of the work of Brown5 011 the stabilities of double bonds, esn YJ. endo, in five- and six-me::i;3ersr! rings has beer1 :~ttempted on these t;yo p i r s of alcohols i:i the absence of experimental evidcnce. It has been predicted that in the six-mem5a-ed riiig series the primary alcohol I1 ( x = 2) should be inore s t i b k in a potential anionotropic system and, conversely, the secondary alcohol I (x = 1) should be favored in the five-membered ring series.6 \Ye wish to report that in a given series both alcohols were unstable t o wid and were co.i\w-tctl
to their isomeric 2-methylcycloalkanone (111).
I (x = 1 or 2 )
111 (x = 1 or 2)
In early experiments, in the formation of I and 11, the alcoholate complexes from the lithium aluminum hydride reductions were worked up with dilute sulfuric acid. The isolated products gave small yields of a semicarbazone. This was in contrast to a high yield of the 2,4dinitrophenylhydrazone (DNPH) of I11 which formed immediately with a 554 solution of the reagent in 50y0sulfuric acid at room temperature. The formation of a semicarbazone could not be observed when the lithium aluminum-alcohol complex was decomposed by the weakly alkaline Rochelle salt.' However, the alcohols (I and 11) retained the property of precipitation with the acid 2,4-dinitrophenylhydrazine solution. The secondary alcohols (I) reacted more rapidly than the primary (11) and gave slightly higher yields, both giving the same DNPH of 111.'
( 7 ) R. E. Lutz and J . S . Gillespie, THISJ O U R N A L , 72, 2002 (1950). T h e reported reduction of dibenzoylethylene with lithium aluminum (1) This work was supportcd t,y irititutional grants f r o m T h e hydride and sulfuric acid hydrolysis gave 1,4-diphenyl-2-butene-1,4American Cancer Society, Inc., 'l'lie Aniericzn Cancer Siociety. S u u t h diol and 1,4-diphenylbutan-l-ol-4-one.T h e latter was presumably eastern Michigan Division and t h e Kresge Foundation. derived from a stable enolate of a 1,4-reduction. Using Rochelle salt ( 2 ) To whom inquiries should be addressed. hydrolysis we obtained similar results. Acid treatment of t h e un75, , '3:iO, 3723 ( 3 ) A S . Dreiding and J. A . Hartman, THISJ O U R N A L saturated diol gave a spectrum typical of a styrene chromophore (1!G3) 213 nlii). (i:: 2: 5 2x inp) and not t h a t of t h e hydroxy ketone ( 4 ) IC. .A. Dmude, Uua;L,Rez., 4 , 404 ( l ~ l > O ) . :.i) [ I . C. B r o w n , I . IT. Brrwstrr nn
