Application of the N-Dibenzyl Protective Group in the Preparation of β-Lactam Pseudopeptides.

Despite the great importance of β-lactam antibiotics, there is still a limited number of synthetic approaches for the formation of β-lactam⁻containing dipeptides. In this study, we report upon the stereoselective preparation of β-lactam⁻containing pseudopeptides, where different reaction conditions and NH₂ protective groups were tested to obtain compounds that contain 3-amino-azetidin-2-one. We demonstrate that the protective group is essential for the outcome of the reaction. Successful implementation of dibenzyl-protected serine-containing dipeptides through the Mitsunobu reaction can provide the desired products at high yields and stereoselectivity.