T. Chan, C. Anderson Evans, Kimberly A. Belsky
Dec 1, 1996
Citations
0
Influential Citations
5
Citations
Journal
Magnetic Resonance in Chemistry
Abstract
Two isomers of betamethasone 9α‐fluoro‐11β,17α,21‐trihydroxy‐16β‐methylpregna‐1,4‐diene‐3,20‐dione (1), were isolated from the mother liquor of a manufacturing process and were characterized by NMR spectroscopy. They were identified as 8α‐fluoro‐11β,17α,21‐trihydroxy‐16β‐methyl‐9β‐pregna‐1,4‐diene‐3,20‐dione (2) and 14β‐fluoro‐11β,17α,21‐trihydroxy‐16β‐methyl‐8α,9β‐pregna‐1,4‐diene‐3,20‐dione (3). The stereochemistries of 2 and 3 were assigned on the basis of proton–proton and proton–fluorine NOE experiments. The structure of the former was confirmed by x‐ray crystallographic analysis.