1,3-インダンジオンの3分子縮合によるトルキセノン誘導体の生成に伴う4量化、5量化由来生成物の構造 The structures of products due to tetramerization and pentamerization in the self condensation reaction of 1,3-indandione to afford truxenone derivatives.

四塩化チタンを触媒にして1,3-インダンジオン（1）をアニリン類と反応させたところ、トルキセノンのモノ、ジ、およびトリイミノ体のほか、5分子が関与したと思われる高分子量の化合物が得られた。これをX船結晶解析することにより、興味深いスピロ構造の5量体構造を明らかにした。また、アニリンの存在無しに、直接、（1）を四塩化チタンとともに加熱したところ、4量体に相当する生成物を得た。各種機器分析の結果、この4量体構造を明らかにした。これらの生成機構についても議論する。

In the intention to develop new synthetic methods of truxenone derivatives, which are expected as new organic functional materials, the condensation reactions of 1,3-indandione and anilines were investigated. The reaction of 1,3-indandione(1) with p-butylaniline in the presence of TiCl4 and DABCO afforded truxenone-diimine and -triimine together with the compound owing to condensation of three molecules of the aniline and five molecules of 1,3-indandione. The structure of the condensation product was determined by X-ray analysis and was found to have an interesting spiro-structure. When the reaction was carried out without anilines, the truxenone was obtained in a good yield along with the tetramer of 1,3-indandione, that is, truxenone condensed by indan-1,3-dione. The characteristic spectral properties and structural features of these products will be discussed as well as plausible mechanisms of their formation.