9-(2-Oxo-ethyl)-1,4-dioxa-7-aza-spiro[4.5]decane-7-carboxylic acid ethyl ester

ethyl 5-(2-ethylenedioxyethyl)-3-oxopiperidine-1-carboxylate

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

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

ethyl 5-(2-ethylenedioxyethyl)-3-hydroxypiperidine-1-carboxylate