Total synthesis of (+)-kalafungin using a tandem Michael–Dieckmann approach
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