Studies on the Dehydrogenative Polymerizations of Monolignol β-Glycosides. Part 1. Syntheses of Monolignol β-glycosides, (E)-Isoconiferin, (E)-Isosyringin, and (E)-Triandrin

摘要

(E)-4-O-Acetyl coniferyl alcohol was synthesized by the reduction of (E)-4-O-acetyl ferulic acid with sodium borohydride and N,N-dimethylchloromethylenium chloride in 80.2% yield. The glycosylation of (E)-4-O-acetyl coniferyl alcohol with trichloroacetimidoyl 2,3,4,6-tetra-O-pivaloyl-α-D-glucopyranoside in the presence of BF_3-Et_2O in anhydrous CH_2Cl_2, followed by deacylation gave (E)-isoconiferin in high yield. This synthetic method could be applied to the syntheses of other monolignol β-glycosides. As a result, (E)-isoconiferin, (E)-isosyringin, and (E)-triandrin were synthesized from vanillin, syringaldehyde, and p-hydroxybenzaldehyde, respectively, by five reaction steps in high overall yield.