(4R,5S,5aR,5bR,9S,10R,10aS,10bS)-4,9-Diisobutyl-5a,10a-dimethyl-2,7-dioxo-dodecahydro-1,6-dioxa-cyclobuta[1,2:3,4]dicycloheptene-5,10-dicarboxylic acid dimethyl ester 在
sodium hydroxide 作用下,
生成
(2S,3R)-2-[(2S,4S)-3-((1R,2S)-2-Carboxymethyl-1-methoxycarbonyl-4-methyl-pentyl)-2,4-dihydroxy-1,3-dimethyl-cyclobutyl]-3-isobutyl-pentanedioic acid 1-methyl ester