The Dolastatins. 19. Synthesis of Dolaisoleuine
作者:George R. Pettit、Sheo Bux Singh、Jayaram K. Srirangam、Fiona Hogan-Pierson、Michael D. Williams
DOI:10.1021/jo00086a034
日期:1994.4
The synthesis of dolaisoleuine as its tert-butyl ester (Dil-OBu(t)), a beta-methoxy-gamma-amino acid component of dolastatin 10, has been achieved employing as key step an aldol condensation between N-(benzyloxycarbonyl)-N-methyl-(S,S)-isoleucinal and tert-butyl acetate followed by O-methylation. The overall six-step reaction sequence to Dil proved to be convenient for routine preparation of this new amino acid and its stereochemical assignment as (3R,4S,SS)-N,O-dimethylisostatine.