HETEROCYCLES

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

■ Mechanism of the Triplet-Sensitized Photolysis of 1-[1-(1-Naphthyl)ethoxy]-2-pyridone and Related Derivatives

Asako Watanabe, Maya Matsushita, Aya Masuda, Tetsutaro Igarashi, and Tadamitsu Sakurai*

*Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan

Abstract

On irradiation at 366 nm in the presence of benzophenone, the title 2-pyridone derivatives (1) in nitrogen-saturated acetonitrile underwent sensitized decomposition to give arylaldehyde and 2-methoxypyridine in addition to the expected N–O bond cleavage products: 1-arylethanol, arylmethylketone, and 2-pyridone. A comparison of the quantum yields for the benzophenone-sensitized photolysis of 1 with those for the direct photolysis with 313 nm light led us to conclude that the former cleavage products were derived from the methyl shift in a 1-derived singlet caged radical pair, taking place in competition with the hydrogen shift in this pair as well as with the recombination and diffusive separation of this pair. Our conclusion was confirmed by deuterium isotope effects on the limiting quantum yields for 1-arylethanol (‘out-of-cage’ product) and arylaldehyde (‘in-cage’ product).