Enantioselective Total Synthesis of (+)‐Neostenine. Issue 10 (2nd February 2016)

• Record Type: Journal Article
• Authors: Nakayama, Yasuaki; Maeda, Yuichiro; Kotatsu, Masayuki; Sekiya, Ruriko; Ichiki, Masato; Sato, Takaaki; Chida, Noritaka
• Is Part Of: Chemistry. Volume 22:Issue 10(2016)
• Page Start: 3300
• Page End: 3303
• Publication Date: 2016-02-02
• Subjects: alkaloid -- allylic compound -- diol -- sigmatropic rearrangement -- total synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201600058
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A chirality transfer approach using acyclic polyol intermediates for the synthesis of (+)‐neostenine (1 ) has been developed. The sequential Overman/Claisen rearrangement of an allylic 1, 2‐diol was especially useful, installing two contiguous stereocenters with complete diastereoselectivity in a one‐pot sequence. The SmI2 ‐mediated cyclization and the subsequent chemoselective reduction of a lactam moiety accomplished the first enantioselective total synthesis of (+)‐neostenine (1 ). Abstract : 18 steps to alkaloid ! The first enantioselective total synthesis of (+)‐neostenine by a chirality transfer approach using three sigmatropic rearrangements of acyclic polyol intermediates has been reported (see scheme). The sequential Overman/Claisen rearrangement was especially useful to introduce two contiguous stereocenters, including a carbon–nitrogen bond. The reaction took place in a completely stereoselective fashion in a one‐pot sequence.