Benzyl Alcohol → HCID 178484880, compound

Participants

Reaction Steps

N-Methyl-L-histidine was converted with benzyl alcohol in the presence of hydrochloric acid at room temperature into the corresponding benzyl ester and this was reacted according to the procedure described by D. H. Rich et al. in Proc. 9thAmerican Pept. Symp.. Toronto 1985. page 217, with t-butoxycarbonyl-L-phenylalanine in the usual manner. Thereafter, the N-[N-t-butoxycarbonyl)-3-phenyl L-alanyl]-N-methyl-L-histidine benzyl ester obtained was hydrogenated for one hour in the presence of 5% palladium on carbon, to obtain N-[N-(t-butoxy-carbonyl)-3-phenyl L-alanyl]-N-methyl-L-histidine, Rf: 0.2 in a 80:20:3:3 mixture of chloroform, methanol, water and acetic acid. This compound was then reacted in the usual manner with (αS,βS)-β-amino-α-[(S)-2-isopropyl-3-butenyl]cyclohexanepropanol. The crude product obtained was then chromatographed on silica gel with a 20:1:0.1 mixture of methylene chloride, methanol and ammonia, upon which the two epimeric compounds were separated. Recrystallization of the crude product obtained from the first fraction from ether/ methylene chloride/hexane yielded t-butyl [(S)-α-[[(S)-1-[[(1S,2S,4S)-1-(cyclohexylmethyl)-2-hydroxy-4-isopropyl-5-hexenyl] carbamoyl]-2-imidazol-4-ylethyl]methylcarbamoyl]-phenylethyl] carbamate as white crystals of melting point 95°.

Provenance & Evidence