Asymmetric Synthesis of the Ring A Substructure of Genkwadane A

Abstract

A practical approach to the asymmetric synthesis of the ring A substructure of genkwadane A, a daphnane diterpenoid, was developed. This synthesis features the Mukaiyama aldol reaction to introduce the quaternary stereogenic center at C4 and VO(acac)2‐catalyzed Jackson‐Ellman‐Bolm sulfoxidation to deliver the corresponding sulfoxide. The Dieckmann‐type condensation was efficiently promoted by KHMDS and the ring A substructure was finally accomplished through Barton iodination condition.