(2,2,5,5-tetramethylcyclopent-3-en-1-ylidene)hydrazine

2,2,5,5-tetramethylcyclopent-3-ene-1-thione

2,2,5,5-tetramethyl-3,4-bis(2-methyl-1-oxopropan-2-yl)hex-3-enedial

2,2,2',2',5,5,5',5'-octamethyl-[1,1'-bi(cyclopentylidene)]-3'-ene-3,4-diol

3,3,6,6,8,8-hexamethyl-7-(2',2',5',5'-tetramethylcyclopent-3-ene-1-ylidene)-2,4-dioxabicyclo(3.3.0)octane