Synthesis of E- and Z-alkene dipeptide isosteres

Article abstract of DOI:10.1016/S0040-4039(00)73956-6

The synthesis of MeLeu and MeLeu-D-Leu alkene dipeptide isosteres are described. Isosteres with an E-alkene bond were synthesized stereoselectively by employing the [2, 3] Wittig rearrangement to control double bond geometry and C-2 configuration. Z-alkene isosters were obtained as an easily separable mixture of diastereomers via alkylation of a Z-alkene MeLeu-Gly isostere that was obtained using a Z-selective Wittig reaction as the key step. All isosteres are isolated with high stereochemical purity.