Synthesis and crystallographic analysis of meso-2,3-difluoro-1,4-butanediol and meso-1,4-dibenzyloxy-2,3-difluorobutane

Abstract

A large-scale synthesis of meso-2,3-difluoro-1,4-butanediol in 5 steps from (Z)-but-2-enediol is described. Crystallographic analysis of the diol and the corresponding benzyl ether reveals an anti conformation of the vicinal difluoride moiety. Monosilylation of the diol is high-yielding but all attempts to achieve chain extension through addition of alkyl Grignard and acetylide nucleophiles failed.

Keywords

• building block
• epoxide opening
• gauche effect
• organofluorine
• vicinal difluoride