benzyl 7,7-dimethoxy-6-oxo-2-azabicyclo<2.2.2>octane-2-carboxylate

9-(2-ethylenedioxyethyl)-1,4-dioxa-7-azaspiro<4.5>decane

3-Oxo-5-vinyl-piperidine-1-carboxylic acid ethyl ester

9-Vinyl-1,4-dioxa-7-aza-spiro[4.5]decane-7-carboxylic acid ethyl ester

ethyl 3-(1,3-dioxolan-2-ylmethyl)-1,2,3,6-tetrahydropyridine-1-carboxylate