Total Synthesis of (±)-α-Isosparteine,(±)-β-Isosparteine, and (±)-Sparteine from a Common Tetraoxobispidine Intermediate†

…, MA Sephton, C Kilner, LN Zakharov…

Index: Norcross, Neil R.; Melbardis, John P.; Solera, Margarita Ferris; Sephton, Mark A.; Kilner, Colin; Zakharov, Lev N.; Astles, Peter C.; Warriner, Stuart L.; Blakemore, Paul R. Journal of Organic Chemistry, 2008 , vol. 73, # 20 p. 7939 - 7951

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Citation Number: 30

Abstract

The three title alkaloids were separately prepared in stereocontrolled fashion from a common tetraoxobispidine precursor, 3, 7-diallyl-2, 4, 6, 8-tetraoxo-3, 7-diazabicyclo [3.3. 1] nonane (16). Bisimide 16 was generated from malonate via acid promoted cyclization of the Knoevenagel condensation adduct 1, 1, 3, 3-propanetetracarboxamide.(±)-α-Isosparteine (dl-2) was elaborated from 16 in 28% overall yield by a two-directional synthetic sequence ...