Asymmetric synthesis of long chain β-hydroxy fatty acid methyl esters as new elastase inhibitors
作者:Belma Hasdemir、Hülya Çelik Onar、Ayşe Yusufoğlu
DOI:10.1016/j.tetasy.2012.07.004
日期:2012.7
methyl esters with an even carbon chain length of 12–20 1b–5b were synthesized by three different asymmetric reduction methods I, II III from their corresponding β-keto methyl esters 1a–5a with the aim of determining their elastase activities. In method I, chiral catalyst A was prepared from chiral ligand (R)-binaphthol 1, while in method II, chiral catalyst B was synthesized from (2R,3R)-diisopropyl tartrate
本文中,通过三种不同的不对称还原方法I,II III,由相应的β-酮甲基酯1a - 5a合成了碳链长度为12-20 1b - 5b的β-羟基甲基酯,以测定其弹性蛋白酶。活动。在方法I,手性催化剂甲从手性配体(其制备- [R )-联萘酚1,而在方法II中,手性催化剂乙从(2合成[R,3 - [R )-二异丙酒石酸2。手性催化剂B以前未曾用于硼烷的不对称还原或手性β-羟基甲基酯的不对称合成中。在方法III中,通过(R)-Me-CBS恶唑硼烷3催化不对称还原。在所有这些方法中,氢化物转移都是通过BH 3 ·SMe 2进行的。用方法I和(R)合成具有(S)构型的手性羟甲基酯。)-通过方法II和III进行配置。通过手性HPLC分析获得的手性羟基甲基酯的ee%值。方法I,II和III首次应用于长链β-酮甲基酯。根据反应的收率和对映体过量,根据碳链长度和手性催化剂与β-酮甲基酯的可变比例,对还原方法I,