Oxalic Acid → (3S,8R,9S,10R,13S,14S,17S)-10,13-Dimethyl-7-oxo-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthrene-3,17-diyl diacetate

A solution of 5-androstene-3β,17β-diol diacetate (5 g, 13.35 mmol) in a mixture of dry carbon tetrachloride (30 Ml), acetic anhydride (4.5 Ml) and glacial acetic acid (1.25 Ml) was treated while stirring with t-butyl chromate solution (35 Ml). The brown reaction mixture was brought to reflux temperature and further stirred for 12 h. The mixture was then cooled in an ice bath and treated in small portions with 10% oxalic acid solution (75 Ml). After adding a further quantity of solid oxalic acid (5.5 g), the reaction mixture was stirred for 2 h at room temperature. The organic phase was removed and the aqueous phase was extracted with carbon tetrachloride (4×50 Ml). The combined carbon tetrachloride extract was successively washed with 5% sodium carbonate solution (2×25 Ml), water and dried. Removal of solvent under reduced pressure gave a pale yellow solid, which was crystallized from methanol to afford the product 7-oxo-5-androstene-3β,17β-diol diacetate (3.2 g, 61.66%), mp 220-221° C. (lit 216-219° C.) [Singh. H., et al Indian J. Chem. 1969, 7, 1084-1087].

1. additionwas treated
2. temperatureto reflux temperature
3. temperatureThe mixture was then cooled in an ice bath
4. stirringthe reaction mixture was stirred for 2 h at room temperature
5. customThe organic phase was removed
6. extractionthe aqueous phase was extracted with carbon tetrachloride (4×50 Ml)
7. extractionThe combined carbon tetrachloride extract
8. washwas successively washed with 5% sodium carbonate solution (2×25 Ml), water
9. customdried
10. customRemoval of solvent under reduced pressure
11. customgave a pale yellow solid, which
12. customwas crystallized from methanol

ORD-Eintrag

ord-787767ee429845a1bc7de98ef485e922

Quelldatensatz

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08361996B2