Hydrogenation catalyst useful in the production of alpha-6-deoxytetracyclines

摘要

A coordination compound useful as a hydrogenation catalyst, having the formula: <IMAGE> (I) wherein Ph is phenyl; R is hydrogen or C1-C4 alkyl; and X is chloro, bromo or iodo. This compound is particularly useful as a homogeneous hydrogenation catalyst in the production of alpha-6-deoxytetracyclines, particularly the antibiotic doxycycline. The desired alpha-6-deoxy product is produced in high yields and stereospecificities, the process requiring the use of minimal quantities of rhodium metal in the hydrogenation catalyst per mole of the 6-methylenetetracycline hydrogenated.