Enantiomerically pure (-)-(1R,4R,5R,6S)- and (+)-(1S,4S,5S,6R)-7-(tert-butoxycarbonyl)-5,6-exo-isopropylidenedioxy-7- azabicyclo[2.2.1]hept-2-one ((-)-3 and (+)-3) have been obtained from the Diels-Alder adduct of N-(tert-butoxycarbonyl)pyrrole and 2-bromo-1-(p-toluenesulfonyl)acetylene, including the Alexakis optical resolution of ketone ()-3 via formation of cyclic aminals with (1R,2R)diphenylethylenediamine. Compounds (-)-3 and (+)-3 were converted into D- and L-2,3-trans-3,4-cis-4,5-trans-N-(tert-butoxycarbonyl)-5-hydroxymethyl-3, 4-isopropylidenedioxyprolines (-)-4 and (+)4, respectively. Applying the Boc and Fmoc strategies of peptide synthesis, these compounds were used to construct two tripeptides containing the D- or L-2,3-trans-3,4-cis-4,5-trans-3,4-dihydroxy-5-hydroxymethylproline.