76902-35-7 Spiro(furan-3(2H),7'(8'H)-(1H)naphtho(1,8a-c)furan)-2,3',10'(5'H,9'H)-trione, 5-(3-furanyl)-4,5,6',6'a-tetrahydro-8'-methyl-, (3R,5S,6'aS,8'R,10'aR)-