作者:Christopher D. Donner
DOI:10.1016/j.tetlet.2007.10.058
日期:2007.12
A stereoselective synthesis of the antibiotic kalafungin 1 is reported. A key step involved the tandem Michael–Dieckmann reaction between methyl 2-methoxy-6-methylbenzoate 11 and the α,β-unsaturated lactone (R)-6-(2-(tert-butyldimethylsilyloxy)ethyl)-4-methoxy-5,6-dihydropyran-2-one 10, which was prepared from (S)-aspartic acid. The C5 alkyl substituent was introduced by the use of methylmagnesium
据报道,抗生素kalafungin 1的立体选择性合成。关键步骤涉及2-甲氧基-6-甲基苯甲酸甲酯11与α,β-不饱和内酯(R)-6-(2-(叔丁基二甲基甲硅烷氧基)乙基)-4-甲氧基-5之间的串联Michael-Dieckmann反应由(S)-天冬氨酸制备的1,6-二氢吡喃-2-酮10。通过使用甲基溴化镁和随后的立体选择性还原来引入C 5烷基取代基。一连串的氧化反应,继之以酸催化的差向异构化,传递了(+)-卡拉芬净1。