Methanol → 9H-Fluoren-9-ylmethyl N-[(1S)-1-formyl-3-methylbutyl]carbamate

Participants

Reaction Steps

Fmoc-Leucine methyl ester (35 g, 134 mmoles) in dry toluene (250 ml) under N2 is cooled with dry ice/acetone, and 150 ml of 25 % di-isobutyl-aluminum hydride in toluene are added over 30 mins. The mixture is stirred for 20 min in a bath of dry ice/acetone after the addition of the di-isobutyl aluminum hydride, then methanol (15 ml) is added cautiously. The mixture is poured into 1000 ml ice-cold water, shaken and filtered. The toluene is separated and the aqueous phase re-extracted with ether (3×300 ml). Toluene and ether extracts are combined and dried over Na2SO4. The resulting oil is passed rapidly though a silica gel column (3×50 cm) in 1500 ml 15% EtOAc/petrol. The Fmoc-Leu-CHO is obtained as a solid (27.6 g).

Provenance & Evidence