isobutyric 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
isobutyric 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