화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.134, No.3, 1392-1395, 2012
A Unified Route to the Welwitindolinone Alkaloids: Total Syntheses of (-)-N-Methylwelwitindolinone C Isothiocyanate, (-)-N-Methylwelwitindolinone C Isonitrile, and (-)-3-Hydroxy-N-methylwelwitindolinone C Isothiocyanate
As part of a comprehensive strategy to the welwitindolinone alkaloids possessing a bicyclo[4.3.1]decane core, we report herein concise asymmetric total syntheses of (-)-N-methylwelwitindolinone C isothiocyanate (2a), (-)-N-methylwelwitindolinone C isonitrile (2b), and (-)-3-hydroxy-N-methylwelwitindolinone C isothiocyanate (3a) from a common tetracyclic intermediate. The crucial vinyl chloride moiety was installed through electrophilic chlorination of a hydrazone, but only after adjustment of reactivity to circumvent a facile skeletal rearrangement. Selective desulfurization and oxidation of 2a provided access to 2b and 3a, respectively. Notably, this work provides corrected H-1 and C-13 NMR spectral data for 3a.