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