Stereoselectivity in the formation and allylic rearrangement of 8a-methyl- and 8a-ethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalenyl hydroperoxides

Abstract

4a-Methyl- and 4a-ethyl-1,2,3,4,4a,5,6,7-octahydronaphthalene have been subjected to singlet oxygen oxygenation, and the various hydroperoxides which are formed have been characterised. Evidence is presented that the 8aβ-alkyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-4aα-yl hydroperoxides (I; R = Me or Et) rearrange suprafacially and irreversibly in chloroform at 25 °C to give only the 4aβ-alkyl-2,3,4,4a,5,6,7,8,8-octahydronaphthalen-2α-yl hydroperoxides (II). Under the same conditions, the corresponding 8aβ-alkyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-4aβ-yl hydroperoxides rearrange much more slowly. [graphic omitted]