DIOXYGENASE-CATALYZED OXIDATION OF DIHYDRONAPHTHALENES TO YIELD ARENEHYDRATE AND CIS-DIHYDRO NAPHTHALENEDIOLS

Biotransformation of 1,2- and 1,4-dihydronaphthalene substrates, using growing cultures of Pseudomonas putida UV4, resulted in dioxygenase-c atalysed benzylic monohydroxylation, cis-tetrahydro diol and cis-dihyd ro diol formation, trihydroxylation and dehydrogenation; The arene hyd rates, (R)-1,2-dihydronaphthalen-1-ol 5 and (R)-1,4-dihydronaphthalen- 1-ol 7, were isolated as enantiopure metabolites while 1,2-dihydronaph thalen-2-ol 8 was found in almost racemic form. The structure, enantio purity and absolute stereochemistry of these arene hydrates of naphtha lene were confirmed by chemical synthesis. Deuterium labelling studies , and the use of enantiomerically pure arene hydrates 5 and 7 as subst rates, were used to establish the metabolic pathways for the formation of (1R,2S)-1,2-dihydronaphthalene-1,2-diols 2, from both 1,2-dihydron aphthalene 3 and 1,4-dihydronaphthalene 6 substrates.