tert-butyl 4-((Z)-benzylidene)-2-((tert-butoxycarbonyl)imino)-1-(4-methoxybenzyl)-1,3-diazaspiro[4.6]undecane-3-carboxylate

3-(tert-butyl) 8-ethyl 4-((Z)-benzylidene)-2-((tert-butoxycarbonyl)imino)-1-(4-methoxybenzyl)-1,3,8-triazaspiro[4.5]decane-3,8-dicarboxylate

tert-butyl 2-((tert-butoxycarbonyl)imino)-1-(4-methoxybenzyl)-4-((Z)-4-(pentyloxy)benzylidene)-1,3-diazaspiro[4.5]decane-3-carboxylate

N,N'-bis(tert-butoxycarbonyl)-N'-(4-chlorobenzyl)-N''-(1-butan-4-al)guanidine