(4S)-7,7-dimethyl-4-nitrobicyclo[2.2.1]heptan-3-one

(1S,5R,7R)-10,10-Dimethyl-3-((R)-1-methyl-2-phenyl-ethyl)-4-oxa-2-aza-tricyclo[5.2.1.01,5]dec-2-ene

(1S,5R,7R)-10,10-Dimethyl-3-((R)-1-methyl-pentyl)-4-oxa-2-aza-tricyclo[5.2.1.01,5]dec-2-ene

(1S,5R,7R)-3-((R)-sec-Butyl)-10,10-dimethyl-4-oxa-2-aza-tricyclo[5.2.1.01,5]dec-2-ene

(1S,5R,7R)-10,10-Dimethyl-3-((R)-1-methyl-butyl)-4-oxa-2-aza-tricyclo[5.2.1.01,5]dec-2-ene