The general procedure for the synthesis of (R)-2-((1R,4R,4aS,8aS)-4,7-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-1-yl)propionic acid from 2-((1R,4R,4aS,8aS)-4,7-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-1-yl)propanoic acid was as follows. 100 g (0.43 mol) of 2-((1R,4R,4aS,8aR)-4,7-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-1-yl)acrylic acid was dissolved in 800 mL of chloroform. The reaction was carried out overnight at room temperature with 1.5 g of palladium carbon as catalyst under a hydrogen pressure of 1 bar. After completion of the reaction, the reaction mixture was filtered through diatomaceous earth and the filter cake was washed with chloroform. Finally, the solvent was recovered by distillation under reduced pressure to afford 99 g (0.42 mol) of the solid product (R)-2-((1R,4R,4aS,8aS)-4,7-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-1-yl)propionic acid in 98% yield.
