Sodium borohydride → N-(2-((S)-1-Amino-3-(4-hydroxyphenyl)-1-oxopropan-2-ylamino)-2-oxoethyl)-2-(5-(hydroxymethyl)thiazol-2-ylamino)-3-methylbutanamide

Participants

Reaction Steps

To a solution of material from Example 31 in EtOH/H2O (4:1) (2.5 mL) is added sodium borohydride (25.5 mg, 0.674 mmol) in 2 equal portions over 5 min. The resulting light suspension is stirred at room temp for 2 h, quenched with MeOH (3 mL), stirred at room temp for 30 min, quenched with acetone (5 mL), and stirred at room temp for 45 min. All volatiles were evaporated off under a gentle stream of N2 to give the title compound (quantitative yield) that is used in its entirety in the macrocyclization step. LC/MS (Condition A): ret. T=1.45 min, (M+H)+ 450.20.

Provenance & Evidence