(E)-5-Tosyl-4-pentenamide: A vinyl sulfone for the one-pot general synthesis of indolizidine derivatives

Article abstract of DOI:10.1016/S0040-4039(97)00736-3

(E)-5-tosyl-4-pentenamide (3), easily prepared from 4-pentenoic acid by stereoselective iodosulfonylation-dehydroiodination and further amidation with oxalyl chloride and ammonia reacts with sodium hydride at room temperature in DMF and then with 1,3-dielectrophiles such as 1,3-dihalides and α,β-unsaturaled esters to provide stereoselectively differently substituted indolizidines 6.