摘要
The stereoselective syntheses of (Z)-methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-3-butenoates 5a-c were investigated. The reaction of (3-carboethoxy-2-fu-ranyl)-methyltriphenylphosphonium bromide 1 with methyl 2-perfluoroalkynoates 2a-c in the presence of K2CO3 at room temperature gives two adducts, (E)-methyl 3-per-fluoroalkyl-4-( 3-carboethoxy-2-furanyl )-2-triphenylphosphoranylidene-3-butenoates 3a-c and (E)-methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-4-triphenylphos-phoranylidene-2-butenoates 4a-c. (Z)-Methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-3-butenoates 5a-c can be synthesized stereoselectively with high yields when an aqueous DMF solution of 3c, 4c or a mixture of 3a-b and 4a-b was heated at 140℃ for 8 h.
The stereoselective syntheses of (Z)-methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-3-butenoates 5a-c were investigated. The reaction of (3-carboethoxy-2-fu-ranyl)-methyltriphenylphosphonium bromide 1 with methyl 2-perfluoroalkynoates 2a-c in the presence of K2CO3 at room temperature gives two adducts, (E)-methyl 3-per-fluoroalkyl-4-( 3-carboethoxy-2-furanyl )-2-triphenylphosphoranylidene-3-butenoates 3a-c and (E)-methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-4-triphenylphos-phoranylidene-2-butenoates 4a-c. (Z)-Methyl 3-perfluoroalkyl-4-(3-carboethoxy-2-furanyl)-3-butenoates 5a-c can be synthesized stereoselectively with high yields when an aqueous DMF solution of 3c, 4c or a mixture of 3a-b and 4a-b was heated at 140℃ for 8 h.
基金
Supported by the National Natural Science Foundation of China
For part XVII of the series, see Chinese J. of Chem. (to be published)
