A divergent chiron approach for the first total synthesis of (+)-pseudonocardide A, (+)-pseudonocardide C and an epimer of ent-pseudonocardide D

A concise and divergent chiron approach for the first total synthesis of (+)-Pseudonocardide A, (+)-Pseudonocardide C and an epimer of ent-Pseudonocardide D is reported starting from D-ribose. The salient features of this synthesis are a highly Z-selective Wittig olefination, one-pot formation of γ-butyrolactone, and γ-butenolide through [1,4] O-to-O silyl migration followed by lactonization and an intramolecular oxa-Michael reaction.