(6R,7S,8S)-1-Benzyl-7-butyl-1-aza-spiro[5.5]undecan-8-ol

(6S,7S,8R,9S)-7-butyl-8,9-epoxy-1-azaspiro[5.5]undecan-2-one

(2S,1'S)-2-(1'-butylbut-2'-enyl)-6-oxopiperidine-2-carboxylic acid 1-methyl ester

(1'S)-6-oxopiperidine-2-carboxylic acid 1'-methyl-hept-2'-enyl ester

(6S,7S)-7-butyl-11-hydroxy-1-azaspiro[5.5]undec-8-en-2-one