Synthesis of verdinochlorins: a new class of long-wavelength absorbing photosensitizers

Abstract

Reaction of 13²-oxopyropheophorbide a with CH₂N₂ produced three isomeric methoxyverdinochlorins via expansion of the cyclopentanedione ring E; these long-wavelength absorbing verdinochlorins represent the first example of verdins with a reduced pyrrolic ring system, and their structural assignments have been made on the basis of ¹H NMR studies; a mechanism of verdinochlorin formation is discussed.

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