Absorption Spectra of Certain α,β-Unsaturated Ketones, including Benzal Compounds

Abstract

Absorption Spectra of «.^-Unsaturated Cyclic Ketones 1230 trated sulfuric acid and fractionally distilled from metallic sodium.Cyclopentanols.-1-Propylcyclopentanol, m. p. -17.0°, b. p. 72°at 12 mm., d2\ 0.9046, »íod 1.4538, and 1-isopropylcyclopentanol, m. p. 21-22°, b. p. 70°at 15 mm., d"< 0.9135, w"d 1.4560, were prepared, dehydrated over iodine and hydrogenated by standard procedures.A solution of 63 g. of 1-propylcyclopentanol in 70 g. of absolute ethanol was hydrogenated directly to propylcyclopentane over nickel catalyst at 250°under 250 atm. of hydrogen, yielding a two-phase mixture of water, alcohol and propylcycldpentane.1-Allylcyclopentanol was prepared by adding 536 g.(7 moles) of allyl chloride and 504 g. (6 moles) of cyclopentanone in 3000 ml. of dry ether to 146 g. (6 atoms) of magnesium turnings and 1500 ml. of dry ether in a copper

Elucidation of the Relationships between H-Bonding Patterns and Excited State Dynamics in Cyclovalone

“…Indeed, in such a structure neither the ESIPT nor the reketonization mechanisms dominating the decay dynamics of all the previously evaluated keto-enolic curcuminoids can take place. We were able to find only a few papers dedicated to the chemistry of cyclopentanones and cyclohexanones, in which the spectral and intramolecular charge distribution properties of either CYV or chemically related compounds are investigated [41,42,43,44,45]. However, it is established that CYV conserves many of the most significant ground-state biological properties of CURC, including the anti-inflammatory ( i.e.…”

Relationships between Absorption Spectra and Spectra and Chemical Constitution of Organic Molecules.

“…The cyclopropyl group may be considered a chromophore but weaker than an ethylenic bond, since in cyclopropane the bonds are under less strain. This viewpoint (15,63,78,193) is supported by the fact that the color deepens in going from cyclohexane to cyclopropane and also for the series cyclohexanone, cyclopentanone, cyclobutanone, and ketene (20,89,93). In this connection a number of studies (61, 109, 155, 200a, 257a) have shown that the cyclopropyl ring and the epoxy group have chromophoric powers approaching that of an ethylenic bond.…”

“…After studying a number of ,/3-unsaturated carbonyl compounds, Woodward (307) found that the values of Xmax for such compounds can be approximated in Evans and Gillam (81,82,98) and other investigators (14,93,300) have measured the spectra of many ,/3-unsaturated ketones and aldehydes and found additional evidence to substantiate Woodward's table. However, Evans and Gillam found that the aldehydes have a Xmax only 5 µ lower than that of the corresponding ketones, rather than 10 µ.…”

Electrocatalytic hydrogenation of catechol on Rh–Al2O3 in different media — pH-Dependent reduction mechanism for intermediate formation

“…The stability of these intermediates was examined using UV absorption spectra (18,19) and voltammetric data (18,(20)(21)(22) in the different media. To understand the influence of the solution medium on reactivity, a newly improved method developed by our group (23,24) was used to determine the adsorption strength by evaluating Henry constants.…”