Nucleophilic addition of potassium alkynyltrifluoroborates to D-glucal mediated by BF3 x OEt2: highly stereoselective synthesis of alpha-C-glycosides.

Nucleophilic addition of potassium alkynyltrifluoroborates to D-glucal mediated by BF3 x OEt2: highly stereoselective synthesis of alpha-C-glycosides.

Organic letters (2008-10-24)

Adriano S Vieira, Pedro F Fiorante, Thomas L S Hough, Fernando P Ferreira, Diogo S Lüdtke, Hélio A Stefani

ABSTRACT

A convenient, mild and highly stereoselective method for C-glycosidation (alkynylation) of D-glucal with various potassium alkynyltrifluoroborates, mediated by BF3x OEt2 and involving oxonium intermediates, preferentially provides the alpha-acetylene glycoside products with good yields.

MATERIALS

Product Number

Brand

Product Description

83253

Supelco

Boron trifluoride - 1-butanol solution, ~10% in 1-butanol (∼1.3 M), for GC derivatization, LiChropur^™

207934

Sigma-Aldrich

Tetrafluoroboric acid solution, 48 wt. % in H₂O