COMPETING O-H INSERTION AND BETA-ELIMINATION IN RHODIUM CARBENOID REACTIONS - SYNTHESIS OF 2-ALKOXY-3-ARYLPROPANOATES

Rhodium(ll) carboxylate catalysed decomposition of diazo esters 3 and 4 in the presence of alcohols or water results information of 2-alkoxy - or 2-hydroxy-3-arylpropanoates respectively by O-H insertion in comp etition with cinnamates by elimination; the ratio of insertion to elim ination is dramatically affected by the carboxylate ligand on rhodium. Use of methanol-d as the alcohol confirms that the alkene does not ar ise by elimination from the initial alkoxyester product.