SYNTHESIS OF BETA-O-4 LIGNIN MODEL DIMERS AND THEIR CHLORINATED DERIVATIVES

The unknown lignin model dimers with hydroxymethyl group at the para position of the phenoxy moiety and their chlorinated derivatives (compounds 1-13, except 8) have been synthesized. During the preparation of 6 from 5, a by-product was isolated and identified as 9. The compounds 4, 7, and 8 were obtained as a mixture of erythro and threo isomers in the ratio of about 5:4, estimated from their C-13 NMR spectra, and the erythro isomer 8a was crystallized from the mixture. Chlorinated derivatives 12a (erythro) and 12b (threo) were also isolated. Their relative configuration was assigned on the basis of both C-13 and H-1 NMR spectroscopy.