Efficient and Selective Synthesis of (<i>S</i>,<i>R</i>,<i>R</i>,<i>S</i>,<i>R</i>,<i>S</i>)-4,6,8,10,16,18-Hexamethyl- docosane via Zr-Catalyzed Asymmetric Carboalumination of Alkenes (ZACA Reaction)
作者:Gangguo Zhu、Bo Liang、Ei-ichi Negishi
DOI:10.1021/ol703056u
日期:2008.3.1
(S,R,R,S,R,S)-4,6,8,10,16,18-Hexamethyldocosane (1) was synthesized in 11% yield in 11 steps in the longest linear sequence from > or =98% pure (S)-beta-citronellal and 6 additional steps for the preparation of 11 in 23% yield from propene. Five of the six asymmetric carbon centers were generated catalytically and stereoselectively by the ZACA reaction (5 times), one lipase-catalyzed acetylation, and
Synthetic Studies toward the Total Synthesis of Tautomycetin
作者:Danilo Pereira de Sant’Ana、Celso de Oliveira Rezende Júnior、Jean-Marc Campagne、Luiz Carlos Dias、Renata Marcia de Figueiredo
DOI:10.1021/acs.joc.9b01712
日期:2019.10.4
The studies culminating in the synthesis of two large subunits of tautomycetin are described. The first one, fragment C1-C12 that has an anti-1,3-dimethyl system and a terminal diene unit, was accomplished in 10 linear steps in 7.4% overall yield. The second one, fragment C13-C25 which bears the sensitive anhydride framework and the majority of the stereogenic centers, was prepared in 13 linear steps