Synthetic confirmation for the structure of stipulin^†

Abstract

184-186A new diprenylated chalcone, stipulin 1 (5', 3-di-isopentenyl-2',4',4-trihydroxychalcone) has been characterized from the roots of Dalbergia stipulaceal. Synthesis of 8-(2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-6-yl)-2,2-dimethyl-3,4,7,8- tetrahydro-2H,6H-benzo[1,2-b:5,4-b'] dipyran-6-one 3 obtained as a final product of the acid catalysed cyclisation of stipulin provided synthetic confirmation for its structure