25-羟基维生素D_(3)中间体C5缩醛溴化镁的合成

Synthesis of 25-Hydroxy Vitamin D_(3) Intermediate C5 Acetal Magnesium Bromide

3-(1-乙氧基乙氧基)-3-甲基丁烷溴化镁(简称C5缩醛溴化镁)作为格氏试剂,可以用于与醛酮类发生格氏反应获得醇或C=C的医药中间体,而与酯类发生偶联反应则可获得C-C单键的医药中间体。尤其它可作为合成25-羟基维生素D_(3)的C5片段中间体,直接与25-羟基维生素D_(3)的C22片段中间体发生偶联得到25-羟基维生素D_(3)的前体,再经过光照水解异构等步骤得到25-羟基维生素D_(3)。本文主要研究3-(1-乙氧基乙氧基)-3-甲基丁烷溴化镁的合成工艺条件。

3-(1-ethoxyethoxy)-3-methyl butarbromide magnesium(referred to as C5 acetal bromine)as a Grignard reagent,can be used to obtain a Grace reaction with aldone Alcohol or C=C pharmaceutical intermediates,while coupling with esters,a pharmaceutical intermediate of C-C single bonds can be obtained.In particular,it can be used as a C5 fragment intermediate of the synthesis 25-hydroxy vitamin D_(3).It is directly coupled to the C22 fragment intermediate of 25-hydroxy vitamin D_(3) to obtain a precursor of 25-hydroxy vitamin D_(3).25-hydroxy vitamin D_(3) is then obtained by light irradiation,hydrolysis,isomer.This paper mainly studies the synthetic process conditions of 3-(1-ethoxyethoxy)-3-methyl butarbromide magnesium.