1-Naphthaldehyde → N-[2(S)-(t-Butoxycarbonylamino)-3(S)-methylpentyl]-N-(1-naphthylmethyl)glycine methyl ester

Participants

Reaction Steps

N-[2(S)-(t-Butoxycarbonylamino)-3(S)-methyl-pentyl]glycine methyl ester (6, 2.00 g, 6.97 mmol) was dissolved in 1,2-dichloroethane (56 ml) and 3A molecular sieves were added followed by 1-naphthaldehyde (1.89 ml, 13.9 mmol) and sodium triacetoxy-borohydride (6.65 g, 31.4 mmol). The mixture was stirred at ambient temperature for 16 h, and filtered through glass fiber paper and concentrated. The residue was partitioned between EtOAc and sat. NaHCO3 (100 ml/25 ml). The aqueous layer was extracted with EtOAc (3×50 ml). The organic layers were combined, dried (Na2SO4), filtered, and concentrated to give 5.0 g of crude product which was purified by chromatography (SiO2, 15-33% ethyl acetate/hexane) to give 7.

Provenance & Evidence