2-methylbut-(2Z)-enoic acid (3R)-5-methoxy-3,4-dihydro-2,2,8-trimethyl-6-oxo-2H,6H-benzo(1,2-b-5,4-b')dipyran-3-yl ester
2-methylbut-(2z)-enoic acid (3r)-5-methoxy-3,4-dihydro-2,2,8-trimethyl-6-oxo-2h,6h-benzo(1,2-b-5,4-b')dipyran-3-yl ester