(2R,3R,4R,5R)-3,4-dibenzyloxy-N-benzyloxycarbonyl-2-tert-butyldiphenylsilyloxymethyl-5-[(1'R,2'S)-1'-2'-dihydroxy-3'-oxobutyl]pyrrolidine

(2R,3R,4R,5R)-3,4-dibenzyloxy-N-benzyloxycarbonyl-2-tert-butyldiphenylsilyloxymethyl-5-[(1'S,2'R)-1'-2'-dihydroxy-3'-oxobutyl]pyrrolidine

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

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

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