Synthesis of 3(2)-phenyl-substituted methyl E/Z-pyropheophorbide-a's from methyl E/Z-pyropehophorbide-a 13(1)-ketoximes

摘要

Methyl E/Z-pyropheophorbide-a 13(1)-ketoximes 2a,b and their O-acetyl derivatives 3a,b were oxidized with osmium(VIII) oxide to give aldehydes 4a,b and 5a,b, respectively. The Wittig reactions of the aldehyde chlorines 4a,b and 5a,b with benzyltriphenylphosphonium chloride were performed to form the corresponding methyl (3(1)E/Z,13(1)E/Z)-3(2)-phenylpyropheophorbide-a 13(1)-ketoximes 6aa-bb and their O-acetyl derivatives 7aa-bb; hydrolysis of these ketoximes 6aa,ba and 6ab,bb in formic acid produced methyl (E/Z)32-phenylpyropheophorbide-a's 8a,b.