(2R,3R,4aR,8aR)-3-Acetoxy-2-acetoxymethyl-7-methyl-4-oxo-3,4,8,8a-tetrahydro-2H,5H-chromene-4a-carboxylic acid methyl ester 在
camphor-10-sulfonic acid 、
sodium methylate 作用下,
以
四氢呋喃 、
甲醇 为溶剂,
生成 (4aR,8aR,9S,9aR,10aR)-9-Hydroxy-6-methyl-2-phenyl-9-vinyl-4,4a,5,9,9a,10a-hexahydro-8H-1,3,10-trioxa-anthracene-8a-carboxylic acid methyl ester