The substituent structures and characteristic infrared spectra of α-furan esters

The characteristic infrared bands of the alpha- furoic esters, alpha- furancarbinol esters and alpha- furanacrylic esters were assigned, and the changing rules of the IR absorption frequency of the alpha- furan esters with alpha -substituent structure were discussed. The results indicated there are three characteristic bands in alpha- furan ring. The strong absorption at 1 641 cm(-1) is assigned to the C=C double bond stretching mode in the alpha- furanacrylic esters, while the absorption at 973 cm(-1) is the out-of-plane =C-H bending mode for a trans di-substituted alkene, the strong absorption at about 1 713 cm(-1) is assigned to a C=O stretch, and the three strong absorptions near 1 305, 1 260 and 1 165 cm(-1) are due to the symmetric and assymmetric stretching vibrations of C-O-C bond in the ester groups.