2-endo-acetoxy-5-endo-chloro-6-exo-(2-nitrobenzenesulfonyl)-7-oxabicyclo<2.2.1>heptane-2-exo-carbonitrile

Acetic acid (1R,2R,7R,8S,9S)-9-cyano-6-methoxy-7-(2-nitro-benzenesulfonyl)-4-trimethylsilanyloxy-11-oxa-tricyclo[6.2.1.02,7]undec-4-en-9-yl ester

(+/-)-6-ethenyl-7-oxabicyclo<2.2.1>hept-5-en-2-one

(+/-)-2-ethenyl-6,6-(ethylenedioxy)-7-oxabicyclo<2.2.1>hept-2-ene