(2S,5S,6R)-2-Benzyloxymethyl-6-(1-hydroxy-non-2-ynyl)-1-aza-spiro[4.5]decane-1-carboxylic acid tert-butyl ester

(2S,5S)-2-Benzyloxymethyl-5-cyano-pyrrolidine-1-carboxylic acid tert-butyl ester

tert-butyl (2S,5S,6R)-2-benzyloxymethyl-6-{(2R,3R)-3-[(1S)-1-hydroxyheptyl]oxiranyl}-1-azaspiro[4.5]decane-1-carboxylate

tert-butyl (2S,5S,6S)-2-benzyloxymethyl-6-[(3R)-3-hydroxynonyl]-1-azaspiro[4.5]decane-1-carboxylate

tert-butyl (2S,5S,6S)-2-benzyloxymethyl-6-[(1E,3R)-3-hydroxynon-1-enyl]-1-azaspiro[4.5]decane-1-carboxylate