Asymmetric bioreduction of racemic 5,4,7,8-tetrahydro-8-methyl-1,3-dimethoxynaphthalen-6-one to the corresponding chiral beta-tetralols

The synthesis of racemic 5,6,7,8-tetrahydro-8-methyl-1,3-dimethoxynaphthale n-6-one 1 was performed and the bioreduction to the corresponding beta -tet ralols was studied with respect to the stereochemical course and optical pu rity of the products; in particular the 6S,8S enantiomer corresponding to t he dimethyl derivative of the natural compound feroxidin was isolated. The biomass of: Aspergillus niger, Cladosporium cladosporioides, Candida lypoli tica, Bacillus megatherium, Rhodotorula minuta, R. flava, R, rubra, Beauver ia bassiana and Baker's yeast were used as biocatalysts. Relative and absol ute configurations of the obtained beta -tetralols were established by comp arison with those of the natural feroxidin. (C) 2001 Elsevier Science B.V. All rights reserved.