Synthesis of Diacetal Trioxa-cage Compounds via Reaction of Bicyclo[2.2.1]heptenes and Bicyclo[2.2.2]octenes with Dimethyldioxirane

A new entry for the synthesis of diacetal trioxa-cage compounds via oxirane-induced sequential cyclization reaction of 2,3-bis-endo-diacylbicyclo[2.2.1]-5-heptenes and 2,3-bis-endo-diacylbicyclo[2.2.2]-5-octenes is reported. In the case of bicyclo[2.2.2]octenes, sequential cyclization reaction induced by iodine as electrophile failed. We have also demonstrated that dimethyldioxirane can selectively oxidize hemiacetals to give lactones with the secondary hydroxy group intact.