作者:Roy A. Johnson、Milton E. Herr、Herbert C. Murray、William C. Krueger、Loraine M. Pschigoda、David J. Duchamp
DOI:10.1021/jo00052a040
日期:1992.12
The oxygenation of several N-cycloheptylbenzamides by fermentation with the fungus Beauveria sulfurescens (ATCC 7159) has been studied. Structures have been determined by chemical and physical methods. Enantioselectivity was observed m the oxygenation process, and the absolute configurations of optically active compounds have been determined by circular dichroism spectroscopy, X-ray crystallography, and chemical correlation. Oxygenation of N-cycloheptylbenzamide (1) gave N-[(1S)-4-oxocycloheptyl]benzamide (2) and N-[(1S,4S)-4-hydroxycycloheptyl]benzamide (5). A reverse of enantioselectivity in the oxygenation process was observed with the substrate N-cycloheptyl-N-methylbenzamide (3), the primary product being N-methyl-N-[(1R)-4-oxocycloheptyl]benzamide (4). Chemical conversion of ketone 2 into N-methyl-N-[(1,S)-4-oxocycloheptyl]benzamide (14) confirmed the enantiomeric relationship of the oxygenation products 2 and 4. Enantiomeric excesses of the oxygenation products were not determined since crystallization was used extensively in the purification of crude products.