STEREOSELECTIVE CONVERSION OF VALIENAMINE AND VALIDAMINE INTO VALIOLAMINE

Article abstract of DOI:10.1016/0008-6215(85)85122-3

Methods are described for the stereoselective conversion of valienamine (2) and validamine (3) into valiolamine (1a), a new pseudo-amino sugar isolated from the fermentation broth of Streptomyces hygroscopicus subsp. limoneus and which is a stronger α-D-glucosidase inhibitor than 2 and 3.Treatment of the acyclic carbamates (4) of 2 with halogenation reagents led to ring closure to afford the halo cyclic carbamates (6), which were reductively dehalogenated and then hydrolyzed to give 1a.Similar treatment of the exomethylene acyclic carbamate (12), derived from 3 via 8-11, resulted in the formation of halo cyclic carbamates (14a,b), which were converted into 1a.The synthesis of epivaliolamine (1b), the C-1 epimer of 1a, starting from 2 and 3, is also described.