Dolastatins 23: stereospecific synthesis of dolaisoleuine
作者:George R. Pettit、Douglas D. Burkett、Michael D. Williams
DOI:10.1039/p19960000853
日期:——
centres. We report herein highlystereoselective routes to both natural (3R,4S,5S)-dolaisoleuine 2 and its 3S,4S,5S-isomer 14 (Z replaces H) using an asymmetric aldol methodology. Key reaction steps are condensation of chiral α-(methylsulfanyl)acetyloxazolidinone 4d with (S)-N-Z-N-Me-isoleucinal 6 using dibutylboron triflate followed by reductive desulfurization, O-methylation and cleavage of the oxazolidinone
分离自软体动物Dolabella auricularia的非凡的抗肿瘤肽dolastatin 10目前正在临床开发中,并且已经对其总合成进行了进一步的改进。主要的努力是针对设计对多lastatin 10个氨基酸的单元dolaisoleuine 2和dolaproine 3的立体选择路线,每个单元具有三个手性中心。我们在此报告了对天然(3 R,4 S,5 S)-dolaisoleuine 2及其3 S,4 S,5 S的高度立体选择性的途径-不对称异构体14(Z取代H)使用不对称的羟醛方法。关键反应步骤是使用三氟甲磺酸二丁基硼将手性α-(甲基硫烷基)乙酰基恶唑烷酮4d与(S)-N - Z - N -Me-异亮氨酸6缩合,然后进行还原脱硫,O-甲基化并裂解恶唑烷酮助剂以完成简单的反应。路线ñ -benzyloxycarbonyldolaisoleuine 10。通过手性代恶唑烷酮5D为4d中的3
Synthesis and Antitumor Activity of Novel Dolastatin 10 Analogs.
Dolastatin 10 (1) is a potent antineoplastic pentapeptide. Novel dolastatin 10 analogs each modified at one of the constituent amino acid derivatives, were synthesized and their antitumoractivity was evaluated against P388 leukemia in mice. The structuralrequirements for antitumoractivity are discussed. Some of the analogs, 31c, 35c, 38b, and 50c showed excellent activity in vivo. Highly active 50c