(1R,2R,3R,5S,6R,7R,7aR)-1,2-dibenzyloxy-6,7-dihydroxy-3-hydroxymethyl-5-methylpyrrolizidine

(1R,2R,3R,5S,6S,7S,7aS)-6,7-di-O-acetyl-1,2-dibenzyloxy-3-tert-butyldiphenylsilyloxymethyl-6,7-dihydroxy-5-methylpyrrolizidine

(1R,2R,3R,5S,6S,7S,7aS)-6,7-di-O-acetyl-3-acetyloxymethyl-1,2-dibenzyloxy-6,7-dihydroxy-5-methylpyrrolizidine