On the preparation of 2-substituted cephalosporin sulfoxides via anionic intermediates
Abstract
The LDA-generated anions of cephalosporin sulfoxides may give rise to a mixture of C-2- and/or C-4-substituted products owing to the delocalized nature of the negative charge. Under optimized conditions 2α-crotonoyl- and 2α-cinnamoylcephalosporin sulfoxides can be obtained in satisfactory yields, and are useful starting materials for cycloaddition reactions leading to novel analogues with β-lactamase or HLE enzyme-inhibiting properties.