Branched-chain sugars. Part XIII. Synthesis of 4′-O-methylapiin
Abstract
A synthesis of 4′-O-methylapiin is described. This involves the preparation of 4′-O-methyl-7-O-(3-O-benzyl-4,6-O-benzylidene-β-D-glucopyranosyl)apigenin and the reaction of this with 2-O-acetyl-1′,3-di-O-benzyl-D-apio-D-furanosyl bromide, followed by removal of protecting groups from the product. The synthesis now reported unequivocally establishes the correctness of the structure proposed for apiin and the β-configuration for the D-apiosyl unit.