benzyl 3-hydroxy-5-(2-oxoethyl)piperidine-1-carboxylate

5-[1,3]Dioxolan-2-ylmethyl-piperidin-3-ol

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

benzyl (E)-5-(3-ethoxycarbonyl-2-propenyl)-3-hydroxypiperidine-1-carboxylate