Z-Asn-OtBu → L-Asparagine tert-butyl ester

Participants

Reaction Steps

23.6 Grams (73.2 mmols) of Z-Asn-OtBu in 200 ml of ethyl acetate are hydrogenated in the presence of 2 g of palladium carbon (10% Pd) until, after 1 hour, hydrogen is no longer absorbed. The catalyst is filtered off and the filtrate concentrated, whereupon the product, melting at 96°-98° C., crystallizes out. Optical rotation [α]D20 =+2° (c=2.1 in methanol). In the thin-layer chromatogram on silica gel the Rf52 =0.30; Rf45 =0.50.

Provenance & Evidence