An efficient synthesis of bicyclic β-turn dipeptides via a photochemical key step
作者:Pablo Wessig
DOI:10.1016/s0040-4039(99)01249-6
日期:1999.8
A novel synthetic route to bicyclic β-turn dipeptides (BTD) is described. It starts with L-β-benzoylalanine 1, which is N-protected and coupled with proline esters yielding the dipeptides3. Upon irradiation 3a-c undergo a cyclization to the indolizinones 4 in a highly stereoselective manner. 4a and 4c were converted into the N-protected BTD derivatives suited for the peptide synthesis. The absolute