Crystal structure of (R)-6-fluoro-2-[(S)-oxiran-2-yl]chroman.

ABSTRACT: The title compound, C11H11FO2, is a building block in the synthesis of the active pharmaceutical ingredient dl-nebivolol. The synthesis starting from the enanti-omerically pure (R)-6-fluoro-4-oxo-3,4-di-hydro-2H-chromene-2-carb-oxy-lic acid resulted in a mixture of two stereoisomers, namely (R)-6-fluoro-2-[(S)-oxiran-2-yl]chroman and (R)-6-fluoro-2-[(R)-oxiran-2-yl]chroman. The mixture was separated by column chromatography but only one stereoisomer crystallized. The X-ray structure analysis revealed that the solid consisted of the R,S isomer. A similar procedure was repeated for (S)-6-fluoro-4-oxo-3,4-di-hydro-2H-chromene-2-carb-oxy-lic acid and, in this case, the S,R isomer was produced as a crystalline solid. Thus, all four stereoisomers of the title epoxide were obtained and their abso

SUBMITTER: Rousselin Y 

PROVIDER: S-EPMC4571392 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature