REACTION OF P-HYDROXYCINNAMYL ALCOHOLS WITH TRANSITION-METAL SALTS .1. OLIGOLIGNOLS AND POLYIGNOLS (DHPS) FROM CONIFERYL ALCOHOL

Treatment of coniferyl alcohol with iron, cobalt, or manganese salts g ave a variety of oligolignols and polylignols (DHPs). Conditions could be adjusted to favor high or low molecular weight products and to giv e different inter-unit linkage distributions. Oxidation with iron and manganese salts generally gave structures containing beta-O-4, beta-5, and beta-beta linkages. Oxidation with iron and manganese salts under highly alkaline conditions also generated alpha-O-4 structures. The c obalt salt K3Co(CN)(6) was unique in that a novel beta-gamma linkage w as generated in high yield. Reactions in the absence of solvent also r esulted in the formation of oligolignols and DHPs.