The synthesis of 'tyrosyl' peptidomimetics by acid-catalyzed N(1)-C(4) ring opening of 4-(4′-hydroxyphenyl)-azetidine-2-ones

Under acidic conditions, the N(1)-C(4) bond of 4-(4′-hydroxyphenyl)-azetidine-2-ones are cleaved with the formation of a stabilized benzylic carbocation intermediates. The intermediates were reduced by silanes or participated in intramolecular or intermolecular Friedel-Crafts reactions to produce tyrosine mimetics.

Acid-catalyzed N(1)-C(4) bond cleavage and subsequent intermolecular and intramolecular Friedel-Crafts reaction of 4-(4′-hydroxyphenyl)-azetidine-2-ones are described.