反应详情

Ethyl 6,6-ethylenedioxy-2-oxo-6-(2-thienyl)-hexanoate (3 g.) and L-alanyl-L-proline t-butyl ester (2.5 g.) were added to a suspension of freshly activated 4 Å molecular sieve (15 g.) in ethanol (35 ml.) and the mixture was stirred at laboratory temperature for 1 hour. Acetic acid (1.25 ml.) was added, and sodium cyanoborohydride (0.625 g.) was then added in portions during 1 hour. The mixture was stirred at laboratory temperature for 48 hours and then filtered, and the filtrate was evaporated to dryness under reduced pressure. The residue was purified by flash chromatography on a silica gel column using a 40:1 v/v mixture of dichloromethane and methanol as eluant. There was thus obtained as an oil N-[1-ethoxycarbonyl-5,5-ethylenedioxy-5-(2-thienyl)pentyl]-L-alanyl-L-proline t-butyl ester.

1. stirringThe mixture was stirred at laboratory temperature for 48 hours
2. filtrationfiltered
3. customthe filtrate was evaporated to dryness under reduced pressure
4. customThe residue was purified by flash chromatography on a silica gel column
5. additiona 40:1 v/v mixture of dichloromethane and methanol as eluant