Benzyl Alcohol → (S)-N-9-Fluorenylmethoxycarbonyl-N-ethylalanine benzylester

Participants

Reaction Conditions

Reaction Steps

A suspension of 848 mg (2.5 mmol) of (S)-N-Fmoc-N-ethylalanine in 10 mL of dichloromethane was treated with 436 μL (5.0 mmol) of oxalyl chloride followed by a catalytic amount (1 drop) of dimethylformamide. The mixture was stirred for one hour, then concentrated in vacuo. The yellow, oily residue was treated with 10 mL of toluene followed by 517 mg (0.5 mmol) of benzyl alcohol and 669 mg (5.0 mmol) of silver cyanide. The mixture was heated in an 80° C. oil bath with vigorous stirring for 20 minutes, then cooled and filtered through a pad of diatomaceous earth. The filtrate was concentrated, and the residue was purified by silica gel column chromatography, using 10% acetone in hexane as eluant. Ester (23) (810 mg) was obtained as a colorless oil; TLC: Rf =0.28, 15% acetone/hexane; 1H NMR (300 MHz) consistent with structure.

Provenance & Evidence