SYNTHESIS AND CRYSTAL-STRUCTURE DETERMINATION OF MODEL COMPOUNDS FOR THE DIBENZODIOXOCINE STRUCTURE OCCURRING IN WOOD LIGNINS

Model compounds for the dibenzodioxocine structure, a new structural u nit recently discovered in wood lignins, have been synthesised by two different methods, In one route, the 8-membered ring is formed by ring closure of an arylglycerol beta-aryl ether with a 5,5'-biphenyl struc ture in the aryl ether moiety. The other, which gave better yields, in volves a biomimetic oxidative phenol coupling. Crystal structures have been obtained for one beta-aryl ether and of two dibenzodioxocine iso mers, as well as of a product of acid hydrolysis containing a 7-member ed ring structure.