Total synthesis of (.+-.)-isolobophytolide and (.+-.)-crassin by titanium-induced carbonyl coupling
作者:John E. McMurry、Russell G. Dushin
DOI:10.1021/ja00175a031
日期:1990.9
Syntheses of the antitumor cembrane lactones (±)-crassin (1) and (±)-isolobophytolide (2) are reported. The key steps are the titanium-induced pinacol coupling of lactone keto aldehydes 3c and 3t to yield macrocyclic diols without harming the lactone rings also present in the molecules. Compound 3t yields a diol (18a) that is converted into isolobophytolide by epoxide formation and methylenation. Compound