A Concise Enantioselective Synthesis of a Key A-Ring Synthon for 1α-Hydroxyvitamin D<sub>3</sub> Compounds
作者:Hiroko Hiyamizu、Hidenori Ooi、Yoko Inomoto、Tomoyuki Esumi、Yoshiharu Iwabuchi、Susumi Hatakeyama
DOI:10.1021/ol006982u
日期:2001.2.1
[figure: see text] This report describes a concise enantioselective synthesis of the A-ring synthon for the synthesis of 1 alpha-hydroxyvitamin D3 compounds. The synthesis involves two notable transformations: (I) stereoselective construction of the enol triflate from the vinyl ketone by Michael addition of Ph2P(O)Li followed by in situ triflation of the resulting enolate and (II) palladium-catalyzed
[图:见正文]该报告描述了用于合成1α-羟基维生素D3化合物的A环合成子的简明对映选择性合成。合成涉及两个显着的转化:(I)通过迈克尔加成Ph2P(O)Li从乙烯基酮中立体选择性地从乙烯基酮构筑烯醇三氟甲磺酸酯,然后对所得烯醇化物进行原位三氟甲磺酸酯化,以及(II)钯催化的Heck型环化烯醇三氟甲磺酸。