A Practical Synthesis of the Dihydroxyethylene Dipeptide Isostere, (2S, 3R, 4S) 2-[(tert-Butyloxycarbonyl)amino]-1-cyclohexyl-3,4-dihydroxy-6-methylheptane, from D-Isoascorbic Acid
作者:William R. Baker、Stephen L. Condon
DOI:10.1016/s0040-4039(00)91679-4
日期:1992.3
)-5-hydroxymethyl-1,3-dioxolane (3b), in 24 and 32% overall yield, respectively. Alcohol 3b was readily prepared from inexpensive and commercially available D-isoascorbic acid in four steps. The synthesis featured a stereoselective addition of cyclohexylmethyllithium to the dimethyl hydrazone of (4S,5S)-2,2-dimethyl-4-(2-methylpropyl)-5-formyl-1,3-dioxolane (4).
将N-Boc二羟基二肽等排7和它的N-Boc 3-(噻唑-4-基)丙氨酰基衍生物8合成,无需纯化中间体,由(4S,5R)-2,2-二甲基-4-(2- -甲基丙基)-5-羟甲基-1,3-二氧戊环(3b)的总收率分别为24%和32%。醇3b可以很容易地从便宜且可商购的D-异抗坏血酸分四个步骤制备。该合成的特征在于将环己基甲基锂立体选择性地加成到(4S,5S)-2,2-二甲基-4-(2-甲基丙基)-5-甲酰基-1,3-二氧戊环(4)的二甲基中。