Patent ID: 8513395

Claim:
A method for preparing an Eastern portion of an anthocyanin, comprising: reacting an α-functionalized ketone starting material of general formula S-1: wherein LG is a leaving group; R 1 is H, OMe or OPG; R 2 is OPG; R 3 is H, OMe or OPG; and each PG independently denotes a protecting group such that where PG is present in different parts of a compound it may, but does not necessarily, denote the same protecting group; and two adjacent OPG groups may optionally be taken together to form a cyclic moiety; with a sugar anion of general formula: XO − wherein XO − is an anion formed by removal of a proton from an anomeric oxygen atom of a sugar, any other hydroxy groups of the sugar being protected by suitable protecting groups; and optionally removing some or all of the protecting groups; to give an Eastern half intermediate of general formula E-1: wherein R 1′ , R 2′ , R 3′ and X′ are each independently the same as R 1 , R 2 , R 3 and X respectively, or are their deprotected analogues.