CHIRAL BUTENOLIDES IN DIELS-ALDER CYCLOADDITIONS WITH ISOPRENE AND CYCLOPENTADIENE

Article abstract of DOI:10.1016/S0040-4039(00)95525-4

Chiral α, β-butenolides react with isoprene at 125-220 deg C giving a 1:1 mixture of Diels-Alder regioisomers, selectivity being dramatically increased by the use of AlCl3 as catalyst.While these butenolides give no reaction with furan even in the presenceof catalysts, they react smoothly with cyclopentadiene, endo/exo selectivity being temperature dependent.