Preparation of enantiomericly pure racemic norambreinolide (N) includes synthesis of (N) from esclareol oxide yielding a gamma lactionic ring

摘要

The preparation of enantiomericly pure racemic norambreinolide (N) has synthesis of (+)-norambreinolide from esclareol oxide or from farnes lacetone, in 85 and 70 per cent yields. The direct conversion of a cyclic ether enol into a gamma-lactonic ring is based on reaction with molecular oxygen and with an oxygen acceptor.