Cyclopropene, the smallest cycloalkene, has attracted the attention of both theoretical and experimental chemists. Cyclopropene contains 27.7 kcal/mol of olefinic strain energy and 55.2 kcal/mol of strain energy. Consequently, cyclopropenes undergo many unusual reactions such as ring-opening reactions to yield vinyl carbenes, [2+2] dimerization to give tricyclo[3.1.0.02,4]hexanes, ene reactions to form 3-cyclopropylcyclopropenes and coupling dimerization to afford 1,3,5-hexatrienes to release olefinic strain energy. In recent years, we have been researching on the synthesis of calixarenes, 2-nitrothiophene derivatives and tropone derivatives.