(2S,4R)-2-((1S 2R)1-Ethoxycarbonyl-2-vinyl-cyclopropylcarbamoyl)-4-hydroxy-pyrrolidine-1-carboxylic acid tert.butyl ester → (1S,2R)-1-[(2S,4R)-(4-Hydroxy-pyrrolidine-2-carbonyl)-amino]-2-vinyl-cyclopropanecarboxylic acid ethyl ester

Participants

Reaction Steps

Compound 13 was kept in 30% trifluoroacetic acid in dichloromethane and 1% MeOH for 2 hrs before it was concentrated to dryness. The residue was re-dissolved in dichloromethane and during stirring 1N NaOH was added to pH 10-11. The organic layer was separated and concentrated which gave 1.6 g of the title product. HPLC purity ca. 90% M+H+ 269.1.

Provenance & Evidence