bicyclo<3.3.0>-2-octen-6-one

1-Cyano-4-morpholin-4-yl-3,3a,8,8a-tetrahydro-azulene-5,6-dicarboxylic acid dimethyl ester

(3aS,4R,6aR)-4-methylhexahydropentalen-1(2H)-one

3,3a,6,6a-tetrahydro-2H-spiro[pentalene-1,2'-[1,3]dioxolane]

4-Oxo-3,3a,4,5,6,6a-hexahydro-pentalene-1-carbonitrile