本文描述了苔藓抑素环 A 和 B 亚基立体选择性组装的化学选择性和原子经济方法。钌催化的串联烯烃-炔耦合/迈克尔加成反应的开发和应用到苔藓抑素环B的合成我们探讨乙炔化介导的环氧化物的开/ 6-外型-挖环化路径访问的苔藓抑素环A,虽然环 A 最终通过酸催化的串联转缩酮/缩酮化序列提供。此外,还评估了双核锌催化甲基乙烯基酮(MVK)羟醛策略用于构建聚乙酸酯部分。这些方法的使用最终导致了包含环 A 和 B 亚基的北部苔藓抑素片段的快速组装。
The Silylalkyne-Prins Cyclization: Stereoselective Synthesis of Tetra- and Pentasubstituted Halodihydropyrans
作者:Pedro O. Miranda、Miguel A. Ramírez、Víctor S. Martín、Juan I. Padrón
DOI:10.1021/ol060247m
日期:2006.4.1
[reaction: see text] A new type of Prins cyclization using silylated secondary homopropargylic alcohols and aldehydes yielding tetra- and pentasubstituted dihydropyrans is described. The presence of the trimethylsilyl group in the triple bond favors the Prins cyclization and minimizes the 2-oxonia-[3,3]-sigmatropic rearrangement as a competitive alternative pathway. Ab initio theoretical calculations
The metal-mediated propargylation or allenylation of carbonyl compounds is well-adapted to the preparation of homopropargylic or allenylic alcohols, which are multifunctional intermediates in synthetic chemistry. However, the regioselectivity of reactions using propargyl or allenyl metal reagents is difficult to control, owing to the equilibrium between the two species. In our study, propargyl or allenyl
Antiproliferative activity of 4-chloro-5,6-dihydro-2H-pyrans. Part 2: Enhancement of drug cytotoxicity
作者:Leticia G. León、Pedro O. Miranda、Víctor S. Martín、Juan I. Padrón、José M. Padrón
DOI:10.1016/j.bmcl.2007.03.045
日期:2007.6
The Prins reaction was the basis to synthesize functionalized alkyl chlorodihydropyran derivatives. The inexpensive, stable, and environmentally friendly FeCl3 promotes the cyclization. The method represents an efficient and regioselective manner to obtain in a single step chlorovinyl-TMS oxacycles. The in vitro antiproliferative activities of the compounds were examined in the human solid tumor cell lines A2780 (ovarian cancer), SW1573 (non-small cell lung cancer), and WiDr (colon cancer). Overall, the results show an enhancement in the cytotoxicity exhibited by the new analogs when compared to their parental compounds. (C) 2007 Elsevier Ltd. All rights reserved.