Radical Cyclization of β-Alkoxymethacrylates: Expedient Synthesis of (+)-Methyl Nonactate
摘要:
[GRAPHICS]Radical cyclization of the beta-alkoxymethacrylate obtained from 5-benzyloxy-1-iodohexan-3-ol led to the stereoselective preparation of the benzyl ether of (+)-methyl nonactate, demonstrating "2,5-cis" selectivity in the radical cyclization step in forming a tetrahydrofuran ring system and "threo" selectivity in the hydrogen abstraction step.
作者:Jeong、Eun Joo Kang、Lee Taek Sung、Sung Kil Hong、Eun Lee
DOI:10.1021/ja0279646
日期:2002.12.1
A macrodiolide antibiotic pamamycin-607 was synthesized by joining two hydroxy acid components. Three cis-2, 5-disubstituted tetrahydrofuran rings in the molecule were stereoselectively prepared by radical cyclization reactions of beta-alkoxyvinyl ketone intermediates and a beta-alkoxymethacrylate substrate. The key step of the synthesis is characterized by the predominant threo product formation in