(2R,3R,4R)-3,4-Dibenzyloxy-2-benzyloxymethyl-1-(2-phthal-imidoethyl)pyrrolidine (Compound 19) (0.64 g, 1.1 mmol) was dissolved in ethanol (20 ml) and hydrazin, hydrate (0.215 ml, 4.4 mmol) was added. The clear solution was stirred for 4 hours at 40° C. and for 18 hours at room temperature. The white precipitate was filtered off and the filtrate evaporated in vacuo. The residue was partitioned between aqueous hydrochloric acid and methylene chloride. The water phase adjusted to pH 11 with 2 N sodium hydroxide and extracted with methylene chloride (2×100 ml) and with diethylether (100 ml). Drying of the combined organic phases with magnesium sulphate and evaporation of the solvent in vacuo afforded the crude product as an oil. Purification on silica gel (Eluent: Ethyl acetate) gave (2R,3R,4R)-1-(2-aminoethyl)-3,4-dibenzyloxy-2-benzyloxymethylpyrrolidine (0.015 g) as an oil.
