This invention relates to a process for the production of alpha-6-deoxytetracyclines and a process for the preparation of a hydrogenation catalyst which is useful for this purpose. The catalyst in question has the formula: where Ph is phenyl, R is hydrogen or C1-C4 alkyl and X is chlorine, bromine or iodine. This compound is particularly useful as a homogeneous hydrogenation catalyst in the production of alpha-6- deoxytetracyclines, particularly the antibiotic doxicycline. The desired al...

Prepn. of alpha-6-deoxytetracyclines (I) by hydrogenation of corresp. 6-methylenetetracyclines (II) or salts, is effected in the presence of a hydrogenation catalyst comprising a transition metal complex of formula MClx(PPh3)y (III) in mixt. with a trace of Rh: where M is transition metal

A coordination compound useful as a hydrogenation catalyst, having the formula: (I) wherein Ph is phenyl

A process for the hydrogenation of a 6-methylenetetracycline in the production of alpha-6-deoxytetracyclines, particularly the antibiotic doxycycline, in the presence of hydriodotetrakis (triphenylphosphine) rhodium (I) as a homogenous hydrogenation catalyst. 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.

A process for the hydrogenation of a 6-methylene-tetracycline in the production of alpha-6-deoxytetracycline, particularly the antibiotic doxycycline, in the presence of a transition metal complex of the formula MClx(PPh3)y wherein M is preferably Cu, Co or Ni, x is 1 or 2 and y is 1-3, and a trace of rhodium either as the supported metal or as a rhodium salt, as a hydrogenation catalyst. The desired alpha-6-deoxytetracycline product is produced in high yields and stereospecificities. The proces...

A coordination compound useful as a hydrogenation catalyst, having the formula: wherein Ph is phenyl