MICROBIOLOGICAL TRANSFORMATIONS .12. THE STEREOCHEMISTRY OF SOME DERIVATIVES OF 2,6-DIMETHYL-1,2,3,4-TETRAHYDROQUINOLIN-4-OL - SINGLE-CRYSTAL X-RAY ANALYSES OF CIS-1-BENZOYL-4-BENZOYLOXY-2,6-DIMETHYL-1,2,3,4-TETRAHYDROQUINOLINE AND TRANS-1-BENZOYL-4-BENZOYLOXY-2,6-DIMETHYL-1,2,3,4-TETRAHYDROQUINOLINE

Configurational and conformational assignments have been made on cis- and trans 2,6-dimethyl-1,2,3,4-tetrahydroquinolin-4-ol 1 and 2 and the N-benzoyl and N,O-dibenzoyl derivatives 3-6 from NMR spectroscopic measurements and single crystal X-ray crystallographic:analyses of the dibenzoyl derivatives 5 and 6. On the basis of this work, previously isolated products-of the microbial transformations of certain : N-substituted 2-methylated 1,2,3,4-tetrahydroquinolines with the fungi Aspergillus niger and Cunninghamella elegans were characterised. Subsequent incubation of 1-benzoyl-2-methyl-1,2,3,4-tetrahydroquinoline 7 with A. niger and C.: elegans was determined to yield, predominantly, the cis-1-benzoyl-2-methyl-1,2,3,4-tetrahydroquinolin-4 ol 8.