(1R,2S,4R,5S)-1,5-dimethyl-6-(2,3,5,6-tetramethoxy-4-methyl-phenyl)-3,7-dioxobicyclo[4.1.0-]heptane-2-carboxylic acid methyl ester 在
potassium carbonate 作用下,
以
甲醇 为溶剂,
以69%的产率得到(4S,5R,6R)-4-hydroxy-3,5-dimethyl-6-(2,3,5,6-tetramethoxy-4-methyl-phenyl)-5,6-dihydro-4H-pyran-2-carboxylic acid methyl ester