88509-18-6Relevant articles and documents
SYNTHESIS OF MULTI CARBON-13 LABELED DEXAMETHASONE
Crowe, D. F.,Christie, P. H.,DeGraw, J. I.,Fujiwara, A. N.,Grange, E.,et al.
, p. 3083 - 3090 (2007/10/02)
A synthesis of dexamethasone multiply labeled with (13)C about the A ring is described. 16-α-Methyl-17α,20-dihydroxypregn-1,4,9(11)-trien-3,20-dione (1) was blocked as the bismethylenedioxy derivative and degraded to the ring C,D-fragment, Des-A,B-9-keto-16α-methyl-17α,20;20,21-bismethylenedioxypregn-8α-propionic acid (9).Conversion to the enol lactone and condensation with 1-diethylphosphono-4-pentanone-(13)C ethylene ketal followed by methylation and A-ring closure afforded the BMD derivative of 16α-methyl-pregn-4,9(11)-diene-3-one(13)C (14).The steroidal intermediate was further transformed to dexamethasone-(13)C.