Գրեք սա: SYNTHESIS OF THE MANNOSIDASE INHIBITORS SWAINSONINE AND 1,4-DIDEOXY-1,4-IMINO-D-MANNITOL AND OF THE RING CONTRACTED SWAINSONINES, (1S, 2R, 7R, 7AR)-1,2,7-TRIHYDROXYPYRROLIZIDINE AND (1S, 2R, 7S, 7AR)-1,2,7-TRIHYDROXYPYRROLIZIDINE