(8aS,10aS)-6,7-Dimethyl-9-oxo-5,10a-dihydro-8H,9H-xanthene-8a-carboxylic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 在
sodium tetrahydroborate 作用下,
以72%的产率得到(8aR,9S,10aS)-9-Hydroxy-6,7-dimethyl-5,10a-dihydro-8H,9H-xanthene-8a-carboxylic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester