Configurations of Cycloadducts Formed in Asymmetric Intramolecular Diels–Alder Reactions
作者:J. Breu、T. Butz、K.-J. Range、J. Sauer
DOI:10.1107/s010827019601579x
日期:1997.4.15
Intramolecular cycloaddition reactions of two furfuryl fumarates yield, after crystallization, pure diastereomers of oxabicyclo[2.2.1]heptene derivatives which are versatile starting points for the total synthesis of natural products. The crystal structures of the adducts, menthyl (3aS,6R,7R,7aR)-1,3,3a,6,7,7a-hexahydro-3,3-dimethyl-1-oxo-3a,6- epoxyisobenzofuran-7-carboxylate, C21H30O5, and methyl syn-3-tert-butyl-1,3,3a,6,7,7a-hexahydro-1- oxo-3a,6-epoxyisobenzofuran-7-carboxylat, C14H18O5, establish the configuration at the chiral centers and provide insights into the factors controlling the diastereomeric differentiation.