High-yielding TfOH-catalyzed condensation of phenols with aromatic aldehydes at high pressure. A model synthesis of the benzylidene biphenol key skeleton of blepharismins

An approach to the benzylidene biphenol key component of blepharismins, photoreceptor pigments isolated from Blepharisma japonicum, is reported. This method relies on an efficient TfOH-catalyzed condensation of phenols with aromatic aldehydes in EtOH as a solvent at 3 kbar pressure. (C) 2001 Elsevier Science Ltd. All rights reserved.