反应详情

From the product mixture obtained according to the same procedure as mentioned above 12β-hydroxypregna-1,4-dien-3-one-20-carbaldehyde and 12α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde were respectively isolated in the following manner. First, a tubular column, 2.6 cm in inside diameter and 70 cm in length, was packed with a suspension of about100 g of silica gel in about 200 ml of chloroform. Separately, 1.2 g of theabove product mixture was dissolved in about 20 ml of chloroform and insolubles were removed. The chloroform solution was concentrated to about5 ml and then allowed to be adsorbed on the above silica gel column and eluted in sequence with chloroform, a 99:1 (by volume) chloroform-ethanol mixture and a 97:3 (by volume) chloroform-ethanol mixture. 12β-Hydroxypregna-1,4-dien-3-one-20-carbaldehyde was eluted in a fraction covering about the 250 ml to 280 ml portions of the second eluate, i.e. the 99:1 chloroformethanol mixture, and thereafter 12α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde was eluted with thesame eluate in a fraction of about 450 ml to 510 ml. These two aldehydes were discriminated from each other based on the facts that, in thin layer chromatography using a thin layer plate (silica gel 60, F-254 manufacturedby Merck in U.S.A.) and an isooctaneethyl acetate-acetic acid mixture (10:10:2 by volume) as the developing solvent, 12β-hydroxypregna-1,4-dien-3-one-20-carbaldehyde gives a spot corresponding to Rf =about 0.4 and 12α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde gives a spot corresponding to Rf =about 0.34. The chloroform and ethanol were distilled off from each eluate fraction with a rotary evaporator, and the residue was washed with diethyl ether and dried. There were thus obtained about 80 mg of 12β-hydroxypregna-1,4-dien-3-one-20-carbaldehyde and about 360 mg of 12α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde.

1. customFrom the product mixture obtained
2. customwere respectively isolated in the following manner
3. custominsolubles were removed
4. concentrationThe chloroform solution was concentrated to about5 ml
5. washeluted in sequence with chloroform
6. wash12β-Hydroxypregna-1,4-dien-3-one-20-carbaldehyde was eluted in a fraction
7. wash12α-hydroxypregna-1,4-dien-3-one-20-carbaldehyde was eluted with thesame eluate in a fraction of about 450 ml to 510 ml