(2R)-1,2,12,12aα-Tetrahydro-5-hydroxy-2α-isopropenyl-8,9-dimethoxy[1]benzopyrano[3,4-b]furo[2,3-h][1]benzopyran-6(6aαH)-one

(2R)-1,2,12,12aα-Tetrahydro-5-hydroxy-8,9-dimethoxy-2-(1-methylethenyl)[1]benzopyrano[3,4-b]furo[2,3-h][1]benzopyran-6(6aαH)-one