this invention provides novel cephalosporin intermediates , 7β - amino - 3 -- 1 - propen - 1 - y1 ]- 3 - cephem - 4 - carboxylic acid and esters thereof having the general formula ## str1 ## wherein the configuration of the 3 - propenyl group is z sometimes referred to as cis - and r is hydrogen or a conventional carboxy - protected group , or a physiologically hydrolyzable esterifying group , and acid addition salts thereof and the metal salts of the foregoing substance wherein r is hydrogen . these compounds are useful as intermediates for preparation of orally active cephalosporins .