Patent ID: 6864377
Filing Date: 2005-03-08
Classification: C07D,Y02P

Abstract:
1. A process for preparing a procyanidin dimer, which process comprises the steps of: (a) protecting each phenolic hydroxyl group of a catechin monomer or an epicatechin monomer with a removable protecting group which does not deactivate the A ring of the monomer; (b) optionally blocking the C-8 position of the monomer of step (a) with a halo group; (c) activating the monomer of step (a) or step (b) by introducing an acyloxy group at the C-4 position using a lead (IV) salt of an organic acid; and (d) catalytically coupling the monomer of step (c) with an unprotected catechin monomer or an unprotected epicatechin monomer.