反应详情

Ethyl (4S,5S)-5-[(S)-3-methyl-1-(3-methylbutylcarbamoyl)butylcarbamoyl]-2-phenyl-1,3-dioxolane-4-carboxylate (2.07 g) obtained in Example 1 was dissolved in acetic acid (40 ml). Palladium black (0.40 g) was added to the resultant solution, and the solution was strongly stirred at room temperature for 60 hours under a hydrogen flow at 4.1 atm. After the catalyst was filtered off, the filtrate was condensed under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (a developing solvent; hexane:ethyl acetate=1:1→1:3) to obtain 1.38 g of a target compound. NMR data of the compound was as follows.

1. filtrationAfter the catalyst was filtered off
2. customcondensed under reduced pressure
3. customto obtain a crude product
4. customThe crude product was purified by silica gel column chromatography (a developing solvent