Conrow RE, Dillow GW, Bian L, Xue L, Papadopoulou O, Baker JK, Scott BS. Corticosteroid decomposition via a mixed anhydride.
J Org Chem 2002;
67:6835-6. [PMID:
12227821 DOI:
10.1021/jo020282g]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxidation of dexamethasone in an aqueous suspension by air during prolonged storage produces the 17alpha-formyloxy-17beta-carboxylic acid 4. A pathway to 4 is proposed that involves Baeyer-Villiger-type oxidation of keto aldehyde 1 to mixed anhydride 5, followed by intramolecular formyl transfer. Synthetically, acid 3 was reacted with N,N'-carbonyldiimidazole followed by triethylammonium formate in order to generate the transient anhydride 5 en route to an authentic sample of 4.
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