Epoxides are essential building blocks in organic chemistry. The epoxidation of unsubstituted cyclic dienes 2, 3, 4 and triene 5 using dimethyldioxirane (1a) and its trifluoro analog 1b methyl(trifluoromethyl)dioxirane has been investigated. The excellent yields obtained (90–98%) are accompanied by outstandingly high diastereoselectivities (90–98%). Interpretation of results based upon the early idea
The reaction of trans-diepoxycyclopentane with azide leads in methanol to the expected azidohydrins; a 1,4-adduct with a 'central' epoxy group is also formed. When the reaction is carried out in acetone/water 1:1, an additional product, which is the acetonide of an azido-trihydroxycyclopentane, is observed. This compound must have been formed by participation of the solvent followed by cyclization.