Cationic bis(oxazoline)Cu(II) Lewis acid catalysts. Enantioselective furan Diels-Alder reaction in the synthesis of ent-shikimic acid

Article abstract of DOI:10.1016/S0040-4039(96)02259-9

The highly enantioselective Diels-Alder reaction between acryloyl oxazolidinone and furan, catalyzed by cationic bis(4-tert-butyloxazoline)Cu)(II) complex 1, is presented. Though the reaction equilibrates rapidly at -20°C, reaction at -78°C permits isolation of the kinetic product mixture. The synthetic utility of the reaction is demonstrated by the conversion of the cycloadduct to ent-shikimic acid.