Dioxygenase-catalysed oxidation of dihydronaphthalenes to yield arene hydrate and cis-dihydro naphthalenediols

Abstract

Biotransformation of 1,2- and 1,4-dihydronaphthalene substrates, using growing cultures of Pseudomonas putida UV4, resulted in dioxygenase-catalysed benzylic monohydroxylation, cis-tetrahydro diol and cis-dihydro diol formation, trihydroxylation and dehydrogenation. The arene hydrates, (R)-1,2-dihydronaphthalen-l-ol 5 and (R)-1,4-dihydronaphthalen-l-ol 7, were isolated as enantiopure metabolites while 1,2-dihydronaphthalen-2-ol 8 was found in almost racemic form. The structure, enantiopurity and absolute stereochemistry of these arene hydrates of naphthalene were confirmed by chemical synthesis. Deuterium labelling studies, and the use of enantiomerically pure arene hydrates 5 and 7 as substrates, were used to establish the metabolic pathways for the formation of (1R,2S)-1,2-dihydronaphthalene-l,2-diols 2, from both 1,2-dihydronaphthalene 3 and 1,4-dihydronaphthalene 6 substrates.