Total synthesis and identification of two diastereoisomers of 1-methyl-2-[N-(p-tolylsulfonyl)-2-pyrrolidinyl]ethyl β-l-fucopyranoside

The reaction of a racemic mixture of (2R,2′S)- and (2S,2′R)-N-(p-tolylsulfonyl)-2-pyrrolidinyl-2-propanol, prepared from (S)-proline, with 2,3,4-tri-O-acetyl-α-l-fucopyranosyl trichloroacetimidate led to both diastereoisomers of the title compound after O-deacetylation.