HERBERT0. HOUSE AND
3972
[CONTRIBUTION FROM TfIE DEPARTMENT O F CHEMISTRY,
w.FRANKLLY GILhfORE
Vol. 83
MASSACHUSETTS INSTITUTE O F TECHNOLOGY, CAMBRIDGE 39,I f ASS.]
Application of the Favorskii Rearrangement to 2,3-Epoxycyclohexanones BY HERBERT 0. HOUSE AND W. FRANKLIN GILMORE~ RECEIVED OCTOBER 31, 1960 The reactioiis of isophorone oxide and piperitone oxide with sodium methoxide or potassium hydroxide in methanol or methanol-water mixtures have been studied. Under these conditions each oxide afforded y-hydroxy acid derivatives corresponding t o a non-stereospecific Favorskil rearrangement. Two abnormal displacement products 12 and 13 were obtained from piperitone oxide. The reaction of piperitone oxide with potassium t-butoxide in 1,2-dimethoxyethane yielded products corresponding to a stereospecific Favorskil rearrangement.
I t was apparent that a study of the rearrangement of a 2,3-epoxycyclohexanone such as 1 might provide a unique opportunity to determine the stereochemistry of a Favorskil rearrangement3 in a cyclic system in which the group being displaced was not bonded to a tertiary carbon atom. For example the direct displacement mechanism 2 leading to a cyclopropanone intermediate 33,4 should produce only the cis-hydroxy acid derivatives 4 and 5,
This paper reports a study of the reactions of piperitone oxide (1) and isophorone oxide (6) with several bases. For this study a mixture of the epimers of piperitone oxide (1) was employed since these epimers, although separable, were readily equilibrated in the presence of bases (triethylamine in acetone) too weak to cause rearrangement. Reaction of piperitone oxide (1)
13
'
b 2 ,
1 Pd-C
ri q&< q-co2;? 2
1 '
3
,or
