A practical and scaleable total synthesis of the jaborandi alkaloid (+)-pilocarpine
作者:Stephen G. Davies、Paul M. Roberts、Peter T. Stephenson、Helen R. Storr、James E. Thomson
DOI:10.1016/j.tet.2009.07.010
日期:2009.9
The total synthesis of (+)-pilocarpine (as its nitrate salt) has been achieved in nine steps and 30% overall yield starting from racemic 2-(2′,2′-dimethoxyethyl)propane-1,3-diol, which was desymmetrised via an enzymatic protocol. A high yielding synthesis of a key α-ethylidene lactone precursor has been developed, which involves the palladium-catalysed decarboxylation/carbonylation of a 1,3-dioxan-2-one
从外消旋的2-(2',2'-二甲氧基乙基)丙烷-1,3-二醇开始,分9步完成了(+)-pilocarpine(作为其硝酸盐)的总合成,总收率达30%。通过酶促方案去对称化。已经开发了关键α-亚乙基内酯前体的高产率合成,其涉及钯催化的1,3-二恶烷-2-酮的脱羧/羰基化以形成γ-丁内酯环。随后对α-亚乙基内酯进行氢化,引入C(3)-立体化学,得到(+)-pilocarpine和(+)-isopilocarpine的72:28混合物,可通过(+)-pilocarpine硝酸盐的重结晶轻松分离盐。