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

Platinum, foil, light tested, 25x25mm, thickness 0.05mm, as rolled, 99.95%
Platinum, foil, 6mm disks, thickness 0.125mm, as rolled, 99.95%
Platinum, foil, 25x25mm, thickness 0.125mm, as rolled, 99.95%
Platinum, foil, 10mm disks, thickness 0.025mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.0025mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.002mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.003mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.0075mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.0125mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.01mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.025mm, as rolled, 99.95%
Platinum, foil, not light tested, 50x50mm, thickness 0.025mm, as rolled, 99.99+%
Platinum, foil, 15x15mm, thickness 0.2mm, as rolled, 99.95%
Platinum, foil, 25x25mm, thickness 0.125mm, as rolled, 99.99+%
Platinum, foil, 25x25mm, thickness 0.1mm, as rolled, 99.95%
Platinum, foil, 25x25mm, thickness 0.1mm, as rolled, 99.99+%
Platinum, foil, 25x25mm, thickness 0.25mm, as rolled, 99.95%
Platinum, foil, 25x25mm, thickness 0.25mm, as rolled, 99.99+%
Platinum, foil, 25x25mm, thickness 0.25mm, as rolled, 99.999%
Platinum, foil, 30x30mm, thickness 0.2mm, as rolled, 99.95%
Platinum, foil, 50x50mm, thickness 0.125mm, as rolled, 99.95%
Platinum, foil, 50x50mm, thickness 0.125mm, as rolled, 99.99+%
Platinum, foil, 50x50mm, thickness 0.1mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width .4mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width .85mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width 1.2mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width 1.6mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width 2mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width 5mm, as rolled, 99.95%
Platinum, foil, 0.05m coil, thickness 0.025mm, coil width 8mm, as rolled, 99.95%