Organofluorine compounds and fluorinating agents. 27 - New trifluoromethylsubstituted 1,2,3-triazoles linked to D-galactose and D-gulose

The title compounds were synthesized by 1,3-dipolar cycloaddition of 3,3,3- trifluoropropinyl benzene (2) to the azido sugars 2,3,4,6-tetra-O-acetyl-be ta-D-galactopyranosyl azide (1), 6- O-acetyl-4-O-cyclohexylcarbamoyl-2,3-O- ( 2,2,2-trichloroethylidene)-beta-D-gulopyranosyl azide (6), 6-azido-6-deox y-1,2:3,4-di-O-isopropylidene-alpha-D-galactopyranose (12), and methyl 6-az ido-4-O-cyclohexylcarbamoyl-6-deoxy-2,3-O-(2,2,2-trichloroethylidene)-beta- D-gulopyranoside (16), respectively. Because of the dissymmetry of the dipo larophile 2, always two regioisomeric products were obtained, the nucleosid e-analogous compounds 3/4 (from 1) and 7/8 (from 6), respectively, and the reversed nucleosides 13/14 (from 12) and 17/18 (from 16), respectively. Pro tecting group chemistry like transesterification, deacetalation, hydrodechl orination is demonstrated in some cases. Thus, the trichloroethylidene deri vatives 7, 8, 17, and 18 were converted into the corresponding ethylidene d erivatives (9, 10, 19, 20) by treatment with tributylstannane/AIBN. An X-ra y analysis is given for the 1-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranos yl)-4-tri-fluoromethyl-5-phenyl-1,2,3-triazole (4) and for the 1-[6-O-acety l-4-O-cyclohexylcarbamoyl-2,3-O-(2, idene)-beta-D-gulopyranosyl]-4-trifluor omethyl-5-phenyl-1,2,3-triazole (7).