Stereoselective synthesis of the “cyathin” diterpene skeleton via an intramolecular pyrylium ylide-alkene cyclization
作者:Philip Magnus、Lan Shen
DOI:10.1016/s0040-4020(98)01162-4
日期:1999.3
The pyrylium ylide precursor 18, available in eight steps from diethyl adipate, undergoes acid catalyzed cyclization to give the cyathin derivative 4α and no detectable amount of the incorrect diastereomer 4β.