Ti(IV) MEDIATED TRANSESTERIFICATION AND REGIO- AND STEREO-SPECIFIC CYCLOADDITION OF IMINES OF α-AMINO ESTERS. REVERSAL OF NORMAL REGIOCHEMISTRY.

Article abstract of DOI:10.1016/S0040-4039(01)80786-3

Ti(i-PrO)3Cl or Ti(i-PrO)2Cl2 in combination with triethylamine effect regio- and stereo-specific cycloaddition of imines of α-amino methyl esters to methyl acrylate at room temperature with reversal of the normal regiochemistry.Transesterification of the imine ester group competes with cycloaddition leading to a mixture of pyrrolidines bearing C(2) methyl and isopropyl ester substituens.