82535-44-2Relevant academic research and scientific papers
Intermolecularly selective [4+4] photocycloaddition of 2-pyridone mixtures
Sieburth, Scott McN.,Lin, Chao-Hsiung
, p. 1141 - 1144 (1996)
4-Alkoxy-2-pyridones do not undergo [4+4] photodimerization but will react with other 2-pyridones to yield highly functionalized cyclooctadienes with differentiated functional groups.
Reactions Using Micellar Systems. IV. Regioselectivity in the Photodimerizations of 2-Pyridones in Micelles and Reversed Micelles
Kato,Takeshi,Nakamura, Yushin,Morita, Yutaka
, p. 2552 - 2563 (2007/10/02)
Photodimerizations of N-alkyl-2-pyridones (1a-e), N-ω-carboxyalkyl-2-pyridones (1f-h),and N-2'-carboxyethyl-4-alkyl-2-pyridones (1i and 1j) in micellar and reversed micellar systems gave the following results; 1) in the reactions of 1a-e, the cis/trans ratios of dimers increased with decreasing concentration of the probes, with the octyl compound (1d) showing the highest selectivity; 2) in the case of 1f-h, the ratios increased up to 1.0 with decreasing alkyl chain length; 3) below 7.2 mM concentration, 1i gave exclusively the cis dimer, while only the trans dimer was formed when the reaction was carried out in water.The results indicate that the regio-control of the reactions was a result of the alignment effect of micelles on the substrate, and moreover, in both micellar systems, not only the distribution of amphiphilic probes between micellar and bulk (water or cyclohexane) phases but also the orientation and incorporation site of the pyridone moiety play important roles in the regioselectively for the cis dimer.Keywords - N-alkyl-2-pyridone; N-ω-carboxyalkyl-2-pyridone; N-2'-carboxyethyl-4-alkyl-2-pyridone; micelle; reversed micelle; dimer; photodimerization; regioselectivity; alignment effect; amphiphile
Structures of the Four Possible Cycloaddition Products Formed on Photodimerization of N-Alkyl-2-pyridones
Nakamura, Yushin,Kato, Takeshi,Morita, Yutaka
, p. 1187 - 1192 (2007/10/02)
Photodimerization of N-methyl-2-pyridone (1a) in water gave exclusively the four cycloaddition products .In contrast, the reaction in non-aqueous solvents (benzene or ethanol), gave only the anti-dimers.The four dimers (5a)-(8a) were photostable, but showed remarkable differences in their thermal stability: (5a) and (6a) were unchanged when heated under reflux in CHCl3, but (7a) and (8a) rearranged to give an unsymmetrical dimer (9), and symmetrical dimers(10) and (11), respectively; thus, structures (7a) and (8a) possess Cope systems.Structures were assigned on the basis of spectral evidence.Variation of the N-alkyl groups and of reagent concentrations had no influence on the relative yields of the dimers.
