Ermolenko Ludmila, Sasaki N André
Institut de Chimie des Substances Naturelles, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
J Org Chem. 2006 Jan 20;71(2):693-703. doi: 10.1021/jo0521192.
[reaction: see text] A novel versatile method for the synthesis of all eight diastereomerically pure L-hexoses was developed. L-Ascorbic acid was converted to two diastereomers A. These alpha-hydroxy esters were transformed into four gamma-alkoxy-alpha,beta-unsaturated esters C via the intermediates B and subsequent Wittig olefination reactions. Each one of compounds C was subjected to dihydroxylation to provide a set of two diols D. Anti/syn-differentiation in diol formation was manipulated by using (DHQD)2PHAL and (DHQ)2PHAL as chiral ligands. Further two-step reaction sequence affords all eight diastereopure L-hexoses.
[反应:见正文] 开发了一种新颖通用的方法来合成所有八种非对映体纯的L-己糖。L-抗坏血酸转化为两种非对映体A。这些α-羟基酯通过中间体B和随后的维蒂希烯烃化反应转化为四种γ-烷氧基-α,β-不饱和酯C。化合物C中的每一种都进行双羟基化反应以提供一组二醇D。通过使用(DHQD)2PHAL和(DHQ)2PHAL作为手性配体来控制二醇形成中的反式/顺式分化。进一步的两步反应序列可得到所有八种非对映体纯的L-己糖。