@article{oai:soar-ir.repo.nii.ac.jp:00019893,
 author = {Shoji, Taku and Araki, Takanori and Iida, Nanami and Kobayashi, Yoshiaki and Ohta, Akira and Sekiguchi, Ryuta and Ito, Shunji and Mori, Shigeki and Okujima, Tetsuo and Yasunami, Masafumi},
 issue = {9},
 journal = {EUROPEAN JOURNAL OF ORGANIC CHEMISTRY},
 month = {Mar},
 note = {First published: 09 Jan 2018, 2-Formylazulene derivatives have been obtained in good yields by the reactions of 2-methylazulenes with N,N-dimethylformamide dimethyl acetal, followed by oxidative cleavage of the intermediately formed enamines with NaIO4. Vilsmeier formylation of 1-phenyl-3-methylazulenes also afforded the corresponding 2-formylazulenes in moderate yields. The treatment of a 2-methylazulene derivative bearing a formyl group at the 1-position with sodium methoxide led, through a self-condensation reaction, to a trans-1-(azulen-1-yl)-2-(azulen-2-yl)ethylene derivative, the structure of which was verified by single-crystal X-ray diffraction analysis. The 2-formylazulenes obtained were transformed into 2-ethynylazulenes in good yields by a modified Seyferth-Gilbert reaction. The reactivity of a 1-iodoazulene bearing a 2-formyl function in palladium-catalyzed cross-coupling reactions has also been examined., Article, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. 2018(9):1145-1157 (2018)},
 pages = {1145--1157},
 title = {Molecular Transformation of 2-Methylazulenes: An Efficient and Practical Synthesis of 2-Formyl- and 2-Ethynylazulenes},
 volume = {2018},
 year = {2018}
}