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

GF35428406

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

GF92036235

Platinum, foil, 25x25mm, thickness 0.125mm, as rolled, 99.99+%

GF87686173

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

GF30259357

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

GF04529538

Platinum, foil, 50x50mm, thickness 0.125mm, as rolled, 99.99+%

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%

GF77270407

Platinum, foil, not light tested, 50x50mm, thickness 0.003mm, as rolled, 99.95%

GF35841584

Platinum, foil, not light tested, 100x100mm, thickness 0.003mm, as rolled, 99.95%

GF39989176

Platinum, foil, not light tested, 25x25mm, thickness 0.00075mm, permanent polyester support, 99.85%

GF73706058

Platinum, foil, 10mm disks, thickness 0.0125mm, as rolled, 99.95%

GF59323619

Platinum, foil, 15mm disks, thickness 0.01mm, as rolled, 99.95%

GF05324183

Platinum, foil, 8mm disks, thickness 0.1mm, as rolled, 99.99+%

GF61053476

Platinum, foil, 0.2m coil, thickness 0.025mm, coil width 5mm, as rolled, 99.95%

GF80931955

Platinum, foil, not light tested, 25x25mm, thickness 0.005mm, as rolled, 99.95%

GF81015465

Platinum, foil, light tested, 50x50mm, thickness 0.025mm, as rolled, 99.99+%

GF68611237

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

GF40155533

Platinum, foil, light tested, 25x25mm, thickness 0.005mm, as rolled, 99.95%

GF43907799

Platinum, foil, 15mm disks, thickness 0.005mm, as rolled, 99.95%

GF60675442

Platinum, foil, 8mm disks, thickness 0.05mm, as rolled, 99.95%

GF13420257

Platinum, foil, 0.5m coil, thickness 0.025mm, coil width 5mm, as rolled, 99.95%

GF48496977

Platinum, foil, 4mm disks, thickness 0.125mm, as rolled, 99.99+%

GF02519917

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

GF02102948

Platinum, foil, light tested, 25x25mm, thickness 0.025mm, as rolled, 99.99+%

GF83202083

Platinum, foil, 0.2m coil, thickness 0.045mm, coil width .75mm, as rolled, 99.95%

GF02450180

Platinum, foil, not light tested, 50x50mm, thickness 0.00075mm, permanent polyester support, 99.85%

GF06440048

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

GF60594442

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

GF45750944

Platinum, foil, not light tested, 25x25mm, thickness 0.0075mm, as rolled, 99.95%

GF36280021

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