SYNTHETIC APPLICATION OF BIOTRANSFORMATIONS - ABSOLUTE STEREOCHEMISTRY AND DIELS-ALDER REACTIONS OF THE ,2R)-1,2-DIHYDROXYCYCLOHEXA-3,5-DIENE-1-CARBOXYLIC ACID FROM PSEUDOMONAS-PUTIDA

1,cis-2-Dihydroxycyclohexa-3,5-diene-1-carboxylic acid, 2, produced by Pseudomonas putide, U103, was shown via X-ray analysis of its p-bromo benzoylmethyl ester to have (IS 2R) absolute stereochemistry. The ster eo- and regio-selectivity of a series of cycloadditions of the methyl ester 3 (R = Me) the methyl ester acetonide 5 and the hydroxymethylace tonide 6 (R = H) with singlet oxygen, 4-phenyl-4,5-dihydro-3H-1,2,4-tr iazole-3,5-dione, N-phenylmaleimide and nitrosobenzene have been estab lished. The stereochemistry: of the oxygen adduct 7 of 5 was:unambiguo usly assigned by X-ray analysis of 7. The acetonides 5 and 6 (R = H) w ere attacked by the dienophiles anti to the acetonide group. The diol ester 3 underwent attack on the face syn to the diol groups. The regio chemistry of the addition of nitrosbenzene was predominantly with the N-phenyl group distal to the ester function in 3 and 5, but proximal t o the hydroxymethyl group in 6 (R = H).