(2S,4R)-2-[(1R,2R,5R)-2-Hydroxy-2,6,6-trimethyl-bicyclo[3.1.1]hept-(3E)-ylideneamino]-4-methyl-hept-6-enoic acid tert-butyl ester

2-[(1R,2R,5R)-2-Hydroxy-2,6,6-trimethyl-bicyclo[3.1.1]hept-(3E)-ylideneamino]-2-methyl-pent-4-ynoic acid methyl ester

(1R,4R,5R)-4,6,6-trimethyl-4-(trimethylsilyloxy)bicyclo[3.1.1]hept-2-en-3-yl nonaflate