Diisopropylethylamine → 3({6-[17-(1,5-Dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yloxycarbonylamino]-hexanoyl}ethoxycarbonylmethyl-amino)-propionic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

The hydrochloride salt of 3-[(6-Amino-hexanoyl)-ethoxycarbonylmethyl-amino]-propionic acid ethyl ester AC (4.7 g, 14.8 mmol) is taken up in dichloromethane. The suspension is cooled to 0° C. on ice. Diisopropylethylamine (3.87 g, 5.2 mL, 30 mmol) is added to the suspension. To the resulting solution, cholesteryl chloroformate (6.675 g, 14.8 mmol) is added. The reaction mixture is stirred overnight. The reaction mixture is diluted with dichloromethane and washed with 10% hydrochloric acid. The product is purified by flash chromatography (10.3 g, 92%).

Provenance & Evidence