A chiron approach to the total synthesis of (-)-juglomycin A, (+)-kalafungin, (+)-frenolicin B, and (+)-deoxyfrenolicin

摘要

A general, efficient, and common strategy for the synthesis of (-)-juglomycin A, (+)-kalafungin, (+)-frenolicin B, and (+)-deoxyfrenolicin is reported here. The strategy involves the synthesis of a key building block alkyne from a cheap chiral pool material, d-glucono-δ-lactone, D?tz benzannulation, oxa-Pictet-Spengler reaction, and H_2SO _4-mediated epimerization.