N-((1,1-dimethylethoxy)carbonyl)-beta-alanine → (E)-2'-(N-tert.-butoxycarbonyl-beta-alanyl)-2(R)-[1(S)-[(tetrahydro-2(RS)-pyranyloxy)-carbamoyl]-4-phenyl-3-butenyl]-2'-isobutyl-4-methylvalerohydrazide

Participants

Reaction Steps

A solution of 0.459 g of (E)-2(R)-[1(S)-[(tetrahydro-2(RS)-pyranyloxy)-carbamoyl]-4-phenyl-3-butenyl]-2′-isobutyl-4-methylvalerohydrazide in 5 ml of dimethylformamide was cooled to 0° C. and treated with 0.378 g of N-tert.-butoxycarbonyl-β-alanine and 0.383 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodimide hydrochloride. The mixture was stirred at room temperature for 16 hours and diluted with ethyl acetate. The solution was washed in succession with water, 5% citric acid solution and water, dried over anhydrous magnesium sulphate and evaporated. Chromatography on silica gel using ethyl acetate/hexane (1:1) for the elution followed by evaporation gave 0.48 g of (E)-2′-(N-tert.-butoxycarbonyl-β-alanyl)-2(R)-[1(S)-[(tetrahydro-2(RS)-pyranyloxy)-carbamoyl]-4-phenyl-3-butenyl]-2′-isobutyl-4-methylvalerohydrazide in the form of a white foam.

Provenance & Evidence