Total synthesis and biological evaluation of (+)-kalkitoxin, a cytotoxic metabolite of the cyanobacterium Lyngbya majusculaElectronic supplementary information (ESI) available: 1H NMR spectrum of synthetic (+)-kalkitoxin in C6D6. See http://www.rsc.org/suppdata/ob/b4/b404205k/
作者:James D. White、Qing Xu、Chang-Sun Lee、Frederick A. Valeriote
DOI:10.1039/b404205k
日期:——
+-Kalkitoxin, a metabolite of the marine cyanobacterium Lyngbya majuscula, was synthesized from (R)-2-methylbutyric acid, (R)-cysteine, and (3S, 4S, 6S)-3,4,6-trimethyl-8-(methylamino)octanoic acid. A key step in the synthesis was installation of the anti,anti methyl stereotriad by means of a tandem asymmetric conjugate addition of an organocopper species to an alpha,beta-unsaturated N-acyl oxazolidin-2-one
由(R)-2-甲基丁酸,(R)-半胱氨酸和(3S,4S,6S)-3,4,6-三甲基-8- (甲基氨基)辛酸。合成中的关键步骤是通过将有机铜物种串联不对称共轭加成到α,β-不饱和N-酰基恶唑烷-2--2-上,然后原位通过α-甲基化来安装抗,反甲基立体三联体。产生的烯醇。烷基毒素的噻唑啉部分是通过四氯化钛催化的乙烯基取代的酰胺基硫醇的环化反应组装的。