Reaction of ozone with steroidal allylic alcohols: evidence for intramolecular interception of the ‘Criegee carbonyl/carbonyl oxide intermediate’

Abstract

The reaction of 3β-acetoxycholest-5-en-7β-ol with ozone at –70 °C gives 3β-acetoxy-7β-hydroxy-5,7aβ-epoxy-5β-B-homo-6-oxacholestane (3) and 3β-acetoxy-7β-hydroperoxy-5,7aβ-epoxy-5β-B-homo-6-oxacholestane (11) resulting from the interception of a classical carbonyl/carbonyl oxide intermediate by intramolecular nucleophilic attack of the allylic hydroxy group on the carbonyl carbon atom. It is shown also that the two possible modes of cleavage of the primary ozonide are realized.