N-alkyl oxazolidines as stereocontrol elements in asymmetric Diels-Alder cycloadditions of 9-substituted anthracene derivatives

Chiral 9-oxazolidinyl anthracene derivatives have been prepared as single diastereoisomers by condensation of 9-anthraldehyde with the appropriate N-alkyl amino alcohol. Asymmetric Diels-Alder cycloadditions of these with N-methyl maleimide proceeds in good yield and in good diastereoselectivity, the sense of which may be controlled by judicious choice of the N-alkyl group.