Liang-Xian Liu

A Flexible Approach to Protected (4S,5S)-5-Alkyl-1-benzyl-4-benzyloxy-2-pyrrolidinones

Abstract We report in this paper a flexible approach to (4S,5S)-5-alkyl-1-benzyl-4-benzyloxy-2-pyrrolidinones 7 starting from the known 5-alkyl-1-benzyl-4-benzyloxy-5-hydroxy-2-pyrrolidinones 6 . The method is based on TMSCl-mediated reductive dehydroxylation of 6 with Zn(BH4)2, which allows the synthesis of a variety of 2-pyrrolidinones 7 in 48-75% yields with cis/trans diastereoselectivities ranging from 58:42 to 90:10.

F3B · OEt2‐Promoted Intramolecular Si to C Phenyl Group Migration: A Highly Diastereoselective Synthesis of (4S,5S)‐4‐Hydroxy‐5‐phenyl‐2‐pyrrolidinone

Abstract A highly diastereoselective approach to N‐protected cis‐(4S,5S)‐4‐hydroxy‐5‐phenyl‐2‐pyrrolidinone is reported. The key step is a boron trifluoride etherate–promoted chemoselective intramolecular Si→C phenyl group migration.