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

(2S,1'S)-2-(1'-butylbut-2'-enyl)-6-oxomethylpiperidine-2-carbaldehyde

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

(6R,1'S)-6-(1'-butylbut-2'-enyl)-6-hydroxymethylpiperidin-2-one

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