140210-18-0Relevant academic research and scientific papers
X-ray-induced transformation of o-vinylbenzaldehyde and 2-methylbenzocyclobutenone to an o-quinoid ketene and its radical cation
Huben, Krzysztof,Zhu, Zhendong,Bally, Thomas,Gebicki, Jerzy
, p. 2825 - 2831 (1997)
Upon ionization in argon matrices by X-irradiation, o-vinylbenzaldehyde (VBA) partially undergoes transfer of the formyl hydrogen atom to the vinylic CH2 group, thereby forming a quinoketene radical cation of the type previously described (Bally, T.; Michalak, J. J. Photochem. Photobiol. A: Chem. 1992, 69, 185). This process does not manifest itself clearly in the optical spectra because the transitions of the quinoketene cation coincide with the much more intense ones of VBA.+ and are mostly obscured by those. However, the IR spectra show unambiguously that the rearrangement occurs rather efficiently. Also they show that in the course of the X-irradiation, the tautomerized cations are reneutralized to form the quinoketene tautomer of VBA in good yield. The quinoketene and its radical cation were independently obtained from 2-methylbenzocyclobutenone which undergoes spontaneous ring-opening on photolysis and/or ionization. The optical spectra of the radical cations are assigned on the basis of CASPT2 calculations and the different species involved in this study are characterized at the B3LYP/6-31G* level.
Photochemical Reaction of o-Alkylphenyl 1,3-Diketones. A New Method for the Preparation of Benzocyclobutenones
Yoshioka, Michikazu,Arai, Masayuki,Nishizawa, Kaori,Hasegawa, Tadashi
, p. 374 - 375 (1990)
Irradiation of o-alkylphenyl 1,3-diketones (1) in hexane gave benzocyclobutenols (2) which underwent thermal retro-aldol cleavage to yield benzocyclobutenones (3).
Preparation of Benzocyclobutenones via the Photochemical Cyclization of 1-(ortho-Alkylary)-2,2,4-trimethylpentane-1,3-diones
Yoshioka, Michikazu,Momose, Shinobu,Nishizawa, Kaori,Hasegawa, Tadashi
, p. 499 - 503 (2007/10/02)
Irradiation of 1-(ortho-methylaryl)- and 1-(ortho-ethylaryl)-2,2,4-trimethylpentane-1,3-diones 4a-g in hexane gave benzocyclobutenols 10a-g.However, irradiation of 1-(ortho-isopropylaryl)-2,2,4-trimethylpentane-1,3-diones 4i and 4j resulted in no reaction.Irradiation of 1-mesityl-2,2,4-trimethylpentane-1,3-dione 4h gave a complex mixture of products.Pyrolysis of benzocyclobutenols 10a, b, d-f gave benzocyclobutenones 11a, b, d-f and 2,4-dimethylpentan-3-one 2, whereas that of the benzocyclobutenols 10c, g gave the starting 1,3-diketones 4c, g predominantly along with small amounts of benzocyclobutenones 11c, g and the dimethylpentanone 2.
