Alkoxyallene-Based De Novo Synthesis of Rare Deoxy Sugars: New Routes to L-Cymarose, L-Sarmentose, L-Diginose and L-Oleandrose
作者:Malte Brasholz、Hans-Ulrich Reißig
DOI:10.1002/ejoc.200900450
日期:2009.7
Starting from lithiated methoxyallene and lactaldehyde derivatives, the four rare 2,6-dideoxy-hexoses L-cymarose, L-sarmentose, L-diginose and L-oleandrose were synthesized in a stereodivergent fashion. Key steps towards these four target monosaccharides were the oxidative ring openings of allene-derived 2,5-dihydrofurans, diastereoselective carbonyl reductions as well as face-selective hydrogenation
从锂化的甲氧基丙二烯和乳醛衍生物开始,以立体发散方式合成了四种罕见的 2,6-二脱氧己糖 L-cymarose、L-sarmentose、L-diginose 和 L-oleandrose。实现这四种目标单糖的关键步骤是丙二烯衍生的 2,5-二氢呋喃的氧化开环、非对映选择性羰基还原以及表面选择性氢化方案。使用 L-cymarose 和 L-diginose 的噻吩糖基供体的第一次糖基化反应以高产率进行,并具有相当到出色的立体控制。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)