A divergent approach for asymmetric syntheses of (+)-spicigerine, (+)-cassine and their 3-epimers. Issue 6 (11th February 2016)

• Record Type: Journal Article
• Authors: Han, Pan; Si, Chang-Mei; Mao, Zhuo-Ya; Li, Hai-Tong; Wei, Bang-Guo; Du, Zhen-Ting
• Is Part Of: Tetrahedron. Volume 72:Issue 6(2016)
• Page Start: 862
• Page End: 867
• Publication Date: 2016-02-11
• Subjects: Total synthesis -- Spicigerine -- Cassine -- Tandem process -- Chiral aldimine; QPRMGHKASRLPJP-KSZLIROESA-N -- WNTPYSGBPUIOAG-BBWFWOEESA-N -- QPRMGHKASRLPJP-RCCFBDPRSA-N -- WNTPYSGBPUIOAG-GVDBMIGSSA-N; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2015.12.057
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: An efficient approach for asymmetric synthesis of (+)-spicigerine, (+)-cassine and their 3-epimers has been developed through the intramolecular diastereoselective tandem addition/cyclisation process of α-chiral aldimine9 with methylmagnesium bromide and the asymmetric addition of nucleophilic reagents to aminal14. Moreover, the first asymmetric synthesis of (+)-spicigerine has been achieved in this manuscript. In this synthetic strategy, the asymmetric syntheses of (+)-spicigerine and (+)-cassine was achieved in a 14% overall yield and nine steps and an 18% overall yield and seven steps from cheap α-chiral aldimine9, respectively. Graphical abstract: