Asymmetric aminohydroxylation of vinyl indoles: a short enantioselective synthesis of the bisindole alkaloids dihydrohamacanthin A and dragmacidin A
作者:Cai-Guang Yang、Jun Wang、Xiao-Xia Tang、Biao Jiang
DOI:10.1016/s0957-4166(02)00111-8
日期:2002.3
A useful approach for the direct enantioselective synthesis of (S)-N-boc-protected alpha-indol-3-ylglycinols from vinyl indoles using the Sharpless asymmetric aminohydroxylation reaction, with enantioselectivities of up to 94% and isolated yields of up to 65%, is described. Expeditious enantioselective syntheses of hamacanthin A and dragmacidin A have been achieved using the corresponding N-Boc-protected alpha-6-bromo-indol-3-ylglycinol as the key intermediate. Furthermore, the absolute stereochemistry of cis- and trans-dihydrohamacanthin A has been determined through the enantioselective total synthesis of the unnatural enantiomers. (C) 2002 Elsevier Science Ltd. All rights reserved.