Synthesis of topsentolides A2 and C2, and non-enzymatic conversion of the former to the latter
摘要:
The first total synthesis of the marine-derived cytotoxin topsentolide A(2), which eventually culminated in its stereochemical determination, was accomplished in 17 steps from a known chiral alcohol. An improved synthesis of its congener, topsentolide C-2, from a synthetic intermediate of topsentolide A(2) was also performed by utilizing the Yamaguchi lactonization to construct its nine-membered lactone ring. Treatment of epoxide ring-containing topsentolide Ay with HCl/MeOH brought about its quantitative conversion into topsentolide C-2. (C) 2014 Elsevier Ltd. All rights reserved.
Synthesis of topsentolides A2 and C2, and non-enzymatic conversion of the former to the latter
摘要:
The first total synthesis of the marine-derived cytotoxin topsentolide A(2), which eventually culminated in its stereochemical determination, was accomplished in 17 steps from a known chiral alcohol. An improved synthesis of its congener, topsentolide C-2, from a synthetic intermediate of topsentolide A(2) was also performed by utilizing the Yamaguchi lactonization to construct its nine-membered lactone ring. Treatment of epoxide ring-containing topsentolide Ay with HCl/MeOH brought about its quantitative conversion into topsentolide C-2. (C) 2014 Elsevier Ltd. All rights reserved.
Stereochemical assignment of topsentolide C2 by stereodivergent synthesis of its four diastereomers
作者:Ryo Towada、Yusuke Kurashina、Shigefumi Kuwahara
DOI:10.1016/j.tetlet.2013.10.032
日期:2013.12
Four diastereomers of topsentolide C-2, a cytotoxic nine-membered lactone isolated from the marine sponge Topsentia sp., were synthesized stereodivergently from a common chiral seco acid by the combined use of the Yamaguchi and Mitsunobu lactonizations. Comparison of the NMR spectra of the four diastereomers with those of an authentic sample of topsentolide C-2 led to the stereochemical determination of topsentolide C-2 as 8R, 11S, and 12S. (C) 2013 Elsevier Ltd. All rights reserved.
Synthesis of topsentolides A2 and C2, and non-enzymatic conversion of the former to the latter
作者:Ryo Towada、Shigefumi Kuwahara
DOI:10.1016/j.tet.2014.04.040
日期:2014.6
The first total synthesis of the marine-derived cytotoxin topsentolide A(2), which eventually culminated in its stereochemical determination, was accomplished in 17 steps from a known chiral alcohol. An improved synthesis of its congener, topsentolide C-2, from a synthetic intermediate of topsentolide A(2) was also performed by utilizing the Yamaguchi lactonization to construct its nine-membered lactone ring. Treatment of epoxide ring-containing topsentolide Ay with HCl/MeOH brought about its quantitative conversion into topsentolide C-2. (C) 2014 Elsevier Ltd. All rights reserved.