[Synthesis of pentadeutereted pregnanediol glucuronide]

The synthesis of 2,2,3,4,4-pentadeuteropregnanediol glucuronide sodium salt, an isotopically substituted analogue of the main progesterone metabolite, have been accomplished. The starting 5 beta-pregnane-3 alpha, 20 alpha-diol bis-tert-butyldimethylsilyl ether was converted by consecutive selective desilylation and oxidation into 5 beta-pregnane-20 alpha-ol-3-one 20-monoether. The latter's alpha-hydrogen atoms were exchanged for deuteriums by treatment with D2O-MeOD mixture catalysed with sodium carbonate, and 2,2,4,4-tetradeuterated 3-ketone formed was reduced by sodium borodeuteride into 2,2,3,4,4-pentadeuterated pregnanediol 20-silyl ether. The ether was glucuronidated under Koenigs-Knorr method with (2,3,4-tri-O-acetyl-alpha-D-glucopyranosylbromide) uronate in the presence of Ag2O. The completely protected pentadeuterated pregnanediol glucuronide resulted was converted into the above mentioned sodium salt by consecutive hydrofluoric acid hydrolysis and treatment with aqueous sodium bicarbonate solution.