Regiochemistry‐Directed Syntheses of Polyhydroxylated Alkaloids from Chiral Aziridines. Issue 12 (14th September 2015)

• Record Type: Journal Article
• Authors: Eum, Heesung; Choi, Jihye; Cho, Cheon‐Gyu; Ha, Hyun‐Joon
• Is Part Of: Asian journal of organic chemistry. Volume 4:Issue 12(2015:Dec.)
• Page Start: 1399
• Page End: 1409
• Publication Date: 2015-09-14
• Subjects: alkaloids -- asymmetric synthesis -- aziridines -- polyhydroxylated compounds -- regiochemistry; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; 547.005
• DOI: 10.1002/ajoc.201500285
• Languages: English
• ISSNs: 2193-5807

Abstract

Abstract: In this study, two possible regiochemical pathways of aziridine ring opening, termed "regiochemistry‐directed branches for 2‐substituted aziridines" are described, providing easy access to two classes of compound from a common synthetic intermediate. Application of this synthetic strategy, with stereoselective dihydroxylation and reductive amination as the key steps, allowed the asymmetric synthesis of natural and unnatural polyhydroxylated alkaloids including the calyculin fragment C33 –C37, 1, 4‐dideoxy‐1, 4‐imino‐l ‐ribitol and analogues of hyacinthacine, swainsonine, castanospermine, and deoxynojirimycin. The initial domino reactions consisted of aziridine ring opening and debenzylation, and reductive double annulations were established for the preparation of bicyclic pyrrolizidine and indolizidine—represented by 8‐deoxyhyacinthacine and (3 R )‐methyl‐8‐deoxyswainsonine—with remarkable stereoselectivity and in high yield. Abstract : Break a ring, make a ring : Two possible regiochemical pathways of aziridine ring opening provide easy access to two different classes of compounds from a common synthetic intermediate. The new method was used to synthesize a variety of pyrrolidine‐ and piperidine‐based polyhydroxylated natural products and their analogues.