Synthesis and Highly Stereoselective Hydrogenation of the Statin Precursor Ethyl (5S)-5,6-Isopropylidenedioxy-3-oxohexanoate
作者:Vitali I. Tararov、Gerd König、Armin Börner
DOI:10.1002/adsc.200600291
日期:2006.12
-oxohexanoates (2) – a key intermediate in the synthesis of pharmacologially important statins – starting from (S)-malic acid is described. The synthesis of the required initial compound methyl (3S)-3,4-(isopropylidenedioxy)butanoate (1) by Moriwake’s reduction of dimethyl (S)-malate (3) has been improved. Direct 2-C chain elongation of ester 1 using the lithium enolate of tert-butyl acetate has been
描述了从(S)-苹果酸开始大规模制备(5 S)-5,6-(异丙基二烯二氧基)-3-氧己酸(2)-合成重要的他汀类药物的关键中间体的尝试。 。所需的初始化合物甲基(3所述的合成小号)-3,4-(异亚丙二)丁酸甲酯(1)由守分的还原二甲酯(小号) -苹果(3)进行了改进。已显示使用乙酸叔丁酯的烯醇锂将酯1直接2-C链延长是烯醇化物过量3至5倍的成功方法。不幸的是,该产品叔丁基(5蒸馏期间,S)-5,6-(异丙基二烯二氧基)-3-氧己酸酯(2a)不稳定。(5 S)-5,6-(异丙基二烯氧基)-3-氧己酸乙酯(2b)可以用N活化,从(3 S)-3,4-(异丙基二烯氧基)丁酸(7)以克数制得。 N'-羰基二咪唑及随后与Mg(OOCCH 2 COOEt)2的反应。还描述了原位制备后者的便利途径。乙酯(2b)可以有利地通过蒸馏纯化。β-酮酸酯催化加氢的立体化学(2b)合成了许多均相的非手性和手性Rh(I)和Ru(II)配合物,合成了(5