Enantioselective syntheses of vinblastine, leurosidine, vincovaline and 20'-epi-vincovaline
摘要:
The binary indole-indoline alkaloids vinblastine (1), leurosidine (13), 20'-epi-vincovaline (14a), and vincovaline (14b) were obtained by coupling of vindoline (3) to the tetracyclic intermediates 7a, 7b or 22a, 22b, followed by reduction and cyclization steps (60% overall yield for these reactions). The intermediates were obtained by enantioselective establishment of C20' through a first-step Sharpless oxidation (10a,b) and followed by a subsequent diastereomeric separation (20a,b or 21a,b). Alternatively, enantioselective control of the key secodine-type cyclization in the reaction sequence provided the tetracyclic intermediates 54 and 60 for coupling to vindoline. Selective generation of the natural (1, 13, 14a,b) or unnatural (30, 34, 35a,b) atropisomeric forms of the alkaloids was achieved through alternative closures of ring D'. The natural products were also obtained from the higher energy atropisomers by conformational inversion on heating. For the vinblastine synthesis, the overall yield was 22%.
Stereospecific synthesis of the top-half precursor to the antitumor agent vinblastine and a simple bisindole analogue.
作者:Philip Magnus、José Mendoza
DOI:10.1016/s0040-4039(00)91570-3
日期:1992.2
The stereospecific synthesis of a precursor to the top-half of vinblastine is described. Its non-oxidative coupling to m-methoxy-N,N-dimethylaniline provides access to the vinblastine analogue 18.
作者:M. F. Semmelhack、Richard J. Hooley、Christina M. Kraml
DOI:10.1021/ol0618656
日期:2006.11.9
Use of a palladium-mediated alkoxycarbonylation/lactonization process provides a variable route to analogs of the plakortones. Four different analogs, including natural plakortone B, have been synthesized via this route.
Magnus, Philip; Mendoza, José S.; Stamford, Andrew, Journal of the American Chemical Society, 1992, vol. 114, # 26, p. 10232 - 10245
作者:Magnus, Philip、Mendoza, José S.、Stamford, Andrew、Ladlow, Mark、Willis, Paul