A stereocontrolled synthesis of a new class of 3,4,5,6- tetrahydropyrimidine-based chiral amino acids

Article abstract of DOI:10.1016/S0040-4020(99)00177-5

The stereocontrolled synthesis of seven 2-substituted-4-carboxy-3,4,5,6- tetrahydropyrimidines bearing either one chiral center at C-4 or two chiral centers at C-4 and C-8 was performed by condensation of (S)- or (R)- 2,4- diaminobutyric acid (Daba) with iminoethers derived from glycine, (S)- and (R)- serine, (S)- and (R)- tyrosine. Under the conditions reported, epimerization was always completely prevented at the C-4 center, whereas at the C-8 center, it was completely avoided in the case of tyrosine derivatives and considerably diminished for the serine derivatives.