Synthesis and absolute configuration of (S)-(-)- and (R)-(+)-2, 3-dihydro-2-(1-methylethenyl)-6-methoxybenzofuran
Resolution of racemic 2,3-dihydro-2-carboxy-6-methoxybenzofuran (2) by recrystallizations of diastereomeric salts prepared with (S)-(-)-alpha-methylbenzylamine and (R)-(+)-alpha-methylbenzylamine gave the starting materials for the four-step total syntheses of (S)-(-)-2,3-dihydro-2-(1-methylethenyl)-6-methoxybenzofuran (1a) and (R)-(+)-2,3-dihydro-2-(1-methylethenyl)-6-methoxybenzofuran (1b). Their absolute configuration was established by chemical correlation.
Tovar-Miranda
R
Instituto de Ciencias Basicas, Universidad Veracruzana, Apartado Postal 575, Xalapa, Ver., 91000 Mexico, and Departamento de Quimica del Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Apartado 14-7.
Cortes-Garcia
R
Trinidad-Nino
LR
Joseph-Nathan
P