Ring-opening of N-(PhF)serine-derived cyclic sulfamidate 17 was achieved with different nucleophiles (beta -keto esters, beta-keto ketones, dimethyl malonate, nitroethane, sodium azide, imidazole, and potassium thiocyanate) to prepare a variety of amino acid analogs. Two different pathways for ring opening of 17 were elucidated: direct nucleophilic displacement, as well as beta -elimination followed by Michael addition. Furthermore, beta -keto ester and beta -keto ketone products 18k,18m, and 18i were converted to prolines and pyrazole amino acids.