Stereocontrolled Synthesis of (2R,3S)-2-Methylisocitrate, a Central Intermediate in the Methylcitrate Cycle
作者:Dan J. Darley、Thorsten Selmer、William Clegg、Ross W. Harrington、Wolfgang Buckel、Bernard T. Golding
DOI:10.1002/hlca.200390332
日期:2003.12
2-Methylisocitrate (=3-hydroxybutane-1,2,3-tricarboxylic acid) is an intermediate in the oxidation of propanoate to pyruvate (=2-oxopropanoate) via the methylcitrate cycle in both bacteria and fungi (Scheme 1). Stereocontrolled syntheses of (2R,3S)- and (2S,3R)-2-methylisocitrate (98% e.e.) were achieved starting from (R)- and (S)-lactic acid (=(2R)- and (2S)-2-hydroxypropanoic acid), respectively
2- Methylisocitrate(= 3-羟基丁烷-1,2,3-三羧酸)是在丙酸乙酯为丙酮酸(= 2-氧代丙酸乙酯)的氧化的中间通过在细菌和真菌(该甲基柠檬酸循环方案1)。(2 R,3 S)-和(2 S,3 R)-2-甲基异柠檬酸(98%ee)的立体控制合成是从(R)-和(S)-乳酸(=(2 R)-和(2 S)-2-羟基丙酸)。双螺酮(6 S,7 S,15 R)-15-甲基-1,8,13,16-四恶二螺[5.0.5.4] hexadecan-14-one(2a衍生自(R)-乳酸的R)用二异丙基氨基锂脱质子化,得到碳负离子,其与富马酸二乙酯缩合(流程3)。二乙基(2 S)-2-[(6 S,7 S,14 R)-14-甲基-15-氧代-1,8,13,16-四恶二螺[5.0.5.4] hexadec-14的加成构型考虑到富马酸酯缩合的可能过渡态(参见方案2),指定了[ yl] butaned