The synthesis of the AB-type Diels-Alder (DA) monomer 12 is reported whose self-condensation leads to the formation of the linear ladder oligomer 17 and its cyclic congener 18. 18 is the largest [n]cyclacene derivative known (n = 18) and can be obtained by thermal treatment of 17 in yields of up to 45% utilizing the reversibility of the DA cyclization involved. 17 can be considered a “storage form”
据报道AB型Diels-Alder(DA)单体12的合成,其自缩合导致线性梯形低聚物17及其环状同源物18的形成。18是已知的最大[ n ]并四苯衍生物(n = 18),可以通过所涉及的DA环化反应的可逆性对17进行热处理,产率高达45%。17可以视为18的“存储形式” 。