Xuebao Wang

A practical method for the preparation of α′-chloroketones of N-carbamate protected-α-aminoacids

Abstract A practical method for the preparation of α-N-BOC-epoxides from protected amino acid esters based on the Kowalski homologation reaction is described. This procedure can be readily performed on a large scale without the use of hazardous reagents and has allowed preparation of epoxides 3 in multi-kilogram quantities.

Efficient synthesis of (S)-(−)- and (R)-(+)-enantiomers of 15-deoxyspergualin (15-DSG)

Abstract An efficient synthesis of the ( S )-(−)- and ( R )-(+)-enantiomers of 15-deoxyspergualin (15-DSG) is reported. The synthesis involves preparative HPLC separation and subsequent hydrogenolysis of two diastereoisomers 10a and 10b of fully protected 15-DSG penultimates. Alternatively, diastereomerically pure amide 10b (97% de) was also prepared from acid 8b (97% de), which was obtained via crystallization of a 1:1 diastereomeric mixture of 8a and 8b .