Efficient synthesis of 6-prenylcoumarins; total syntheses of suberosin, toddaculin, O-methylapigravin (O-methylbrosiperin) and O-methylbalsamiferone
Abstract
Synthesis of naturally occuring 6-prenylcoumarins 1a, b, 2c, and 3b and their derivatives 6a–c is described, starting from 2-prenyloxybenzaldehydes 4a–c, using a tandem Claisen rearrangement and Wittig reaction.