Synthesis of tamarixetin and isorhamnetin 3-O-neohesperidoside

Two isomeric flavonol 3-O-glycosides, tamarixetin and isorhamnetin 3-O-neohesperidoside (1 and 2), were synthesized. The natural product from Costus spicatus assigned as the former compound is revised to the latter structure.