Anodic electrochemical oxidation of cholic acid.

Anodic electrochemical oxidation of cholic acid.

Steroids (2001-01-09)

A Medici, P Pedrini, A De Battisti, G Fantin, M Fogagnolo, A Guerrini

ABSTRACT

Regioselectivity in the anodic electrochemical oxidation of cholic acid with different anodes is described. The oxidation with PbO(2) anode affords the dehydrocholic acid in quantitative yield after 22 h. 3alpha,12alpha-Dihydroxy-7-oxo-5beta-cholan-24-oic acid (59%) and 3alpha-hydroxy-7,12-dioxo-5beta-cholan-24-oic acid (51%) are obtained stopping the reaction at lower time. The rate of the OH-oxidation is C7 > C12 > C3. The electro-oxidation with platinum foil anode gives selectively the 7-ketocholic acid in 40% yield. On the other hand, the graphite plate anode, varying the reaction conditions, produces selectively the dehydrocholic acid in quantitative yield or the 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholan-24-oic acid (96%) while the 3alpha,7alpha-dihydroxy-12-oxo-5beta-cholan-24-oic acid (34%) is obtained together with the other oxo acids.

MATERIALS

Product Number

Brand

Product Description

GF72819715

Platinum, foil, 25x25mm, thickness 0.25mm, as rolled, 99.99+%

GF87686173

Platinum, foil, 30x30mm, thickness 0.2mm, as rolled, 99.95%

GF17993368

Platinum, foil, 10mm disks, thickness 0.125mm, as rolled, 99.95%

GF35428406

Platinum, foil, 15x15mm, thickness 0.2mm, as rolled, 99.95%

GF37488268

Platinum, foil, 8mm disks, thickness 0.004mm, as rolled, 99.95%

GF63387108

Platinum, foil, 10mm disks, thickness 0.125mm, as rolled, 99.99+%

GF52591462

Platinum, foil, 4mm disks, thickness 0.0075mm, as rolled, 99.95%

GF30259357

Platinum, foil, 25x25mm, thickness 0.125mm, as rolled, 99.95%

GF80498391

Platinum, foil, 4mm disks, thickness 0.01mm, as rolled, 99.95%

GF02519917

Platinum, foil, 6mm disks, thickness 0.0125mm, as rolled, 99.95%

GF00187163

Platinum, foil, 0.1m coil, thickness 0.15mm, coil width .9mm, as rolled, 99.99%

GF55534046

Platinum, foil, 0.05m coil, thickness 0.029mm, coil width .34mm, annealed, 99.99%

GF68611237

Platinum, foil, 0.2m coil, thickness 0.029mm, coil width .34mm, annealed, 99.99%

GF41572414

Platinum, foil, 8mm disks, thickness 0.0075mm, as rolled, 99.95%

GF15087203

Platinum, foil, 0.1m coil, thickness 0.025mm, coil width 1.6mm, as rolled, 99.95%

GF25102897

Platinum, foil, 0.5m coil, thickness 0.045mm, coil width .75mm, as rolled, 99.95%

GF87506208

Platinum, foil, 0.2m coil, thickness 0.025mm, coil width 1.6mm, as rolled, 99.95%

GF05432936

Platinum, foil, 0.05m coil, thickness 0.030mm, coil width .7mm, as rolled, 99.95%

GF96551354

Platinum, foil, 10mm disks, thickness 0.0075mm, as rolled, 99.95%

GF14989641

Platinum, foil, 8mm disks, thickness 0.0125mm, as rolled, 99.95%

GF85654019

Platinum, foil, 8mm disks, thickness 0.005mm, as rolled, 99.95%

GF72782231

Platinum, foil, 50x50mm, thickness 0.1mm, as rolled, 99.99+%

GF07973961

Platinum, foil, 0.5m coil, thickness 0.025mm, coil width .85mm, as rolled, 99.95%

GF89210336

Platinum, foil, 4mm disks, thickness 0.025mm, as rolled, 99.95%

GF06440048

Platinum, foil, 4mm disks, thickness 0.05mm, as rolled, 99.95%

GF61547632

Platinum, foil, 8mm disks, thickness 0.01mm, as rolled, 99.95%

GF83172269

Platinum, foil, 0.05m coil, thickness 0.025mm, coil width .4mm, as rolled, 99.95%

GF60594442

Platinum, foil, 0.5m coil, thickness 0.025mm, coil width 8mm, as rolled, 99.95%

GF36280021

Platinum, foil, 0.2m coil, thickness 0.025mm, coil width .4mm, as rolled, 99.95%

GF84685236

Platinum, foil, 6mm disks, thickness 0.005mm, as rolled, 99.95%