上游原料
3-chloro-3-methyl-1-butyne(1R,4S)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carbonyl chloride7-hydroxy-4-methyl-2H-chromen-2-one7-[(1,1-dimethyl-2-propynyl)oxy]-4-methyl-2H-chromen-2-one4,8,8-trimethyl-2H,8H-pyrano[2,3-f]chromen-2-one(9R,10R)-9,10-dihydroxy-4,8,8-trimethyl-9,10-dihydro-2H,8H-pyrano[2,3-f]chromen-2-one
