Reinvestigation on total synthesis of kaitocephalin and its isomers

Aldol reaction of 2,5-disubstituted pyrrolidine 3b with (R)-Garner aldehyde followed by Sharpless asymmetric dihydroxylation and other four reactions afforded mesylate 8a, which was introduced by an amide group via three ordinary transformations to provide amide 9a. Careful deprotection with AlCl3/Me2S and subsequent HPLC purification furnished kaitocephalin.