Total Synthesis of Nojirimycin

Article abstract of DOI:10.1002/hlca.19820650403

Addition of the nitrone 3 (from 8 and 9) to furane, followed by oxidation with OsO4 and then isopropylidenation gave the fully functionalized glycoside 12 (40percent from 8) via the glycal 10 and the hemiacetal 11.Since the glycoside cleavage of 12, leading to 13 after benzyloxycarbonylation proceeded in a mediocre yield, and since the acetolysis of 12 giving 14 (69percent) was not practical, compound 12 was transformed into the hydroxy ester 17 by sequential hydrogenolysis, hydrolysis and benzyloxycarbonylation (69percent overall).The hydroxy ester 17 was lactonized to give 18 (87percent).Reduction of 18 first with LiBH4 (97percent) and then with H2/Pd gave the keycompound 20 which was transformed into nojirimycin (1) and into 1-deoxy-nojirimycin (2) using prior art.The overall yield of 1 was 19.5percent.