82245-43-0

Upstream product

• 67-56-1 methanol 
• 1009-14-9 phenyl butyl ketone 
• 64498-06-2 phenyl n-butyl α-peroxylactone 
• 917-95-3 t-butylnitrite 
• 130996-82-6 2C₈₀H₉₆O₈*3C₁₁H₁₄O 
• 130996-81-5 1,1,6,6-Tetraphenyl-hexa-2,4-diyne-1,6-diol; compound with 1-phenyl-pentan-1-one 
• 938-87-4 2-methyl-1-phenyl-butan-1-one 
• 1517-15-3 2-methylcyclobutanone 
• 591-51-5 phenyllithium 

Downstream Products

• 27927-59-9 4-hydroxy-1-phenylpentan-1-one 
• 1383116-00-4 4-fluoro-1-phenylpentan-1-one 

Relevant academic research and scientific papers

Phenyliodine diacetate-mediated oxidative cleavage of cyclobutanols leading to γ-hydroxy ketones

Oxidative cleavage of cyclobutanols using PIDA, which leads to efficient entry of γ-hydroxy ketones, is described. When using 2-substituted cyclobutanols, γ-substituted γ-hydroxy ketones are obtained through regioselective C-C bond cleavage.

Influence of cyclodextrin encapsulation on Norrish-Yang photoreaction of valerophenone

In the solid-state Norrish-Yang photoreaction of valerophenone, studied in presence of various cyclodextrins, not only was elimination suppressed, but a remarkable diastereoselectivity was also observed. The predominant formation of one cyclobutanol (C1-trans) is rationalized as being due to a restricted rotational motion of the 1,4-biradical, and also stabilization of the same by hydroxyl groups present in the rim of the cyclodextrin cavity. Additional supports for the coinclusion of a side chain into the γ-CD cavity from molecular minimization calculations and 1H-1H NOESY spectra are also presented.

Surface photochemistry of alkyl aryl ketones: Energy transfer and the effect of a silica-gel surface on electronic states of excited molecules

Alkyl aryl ketones undergo Type II photoreaction both on a silica-gel surface and in solution. The amount of acetophenone produced from valerophenone increases linearly with increase in the amount of valerophenone loaded at coverage below ca 60%. The effect of the alkyl chain length on the Type II photoreactivity of alkyl phenyl ketones on the surface is weak. The relative quantum yields ΦMeAp/ΦAP and ΦMeOAP/ΦΛP on the surface are lower than those in benzene containing 0.5 M pyridine. A silica-gel surface provides a polar reaction medium that makes the energy difference between the lowest n,π* and the upper π,π* triplet states small and may cause the inversion of the nearby n,π* and π,π* triplet states. The filter effect is trivial in surface photochemistry when all loaded molecules are in the monomolecular layer. The energy transfer processes are observed in the valerophenone-p-methylvalerophenone and valerophenone-p-methoxyvalenophonone systems in which the internal filter effects are so strong that the energy transfer processes cannot be observed directly in solution. Although the Stern-Volmer quenching kinetics would be applicable to the photoreaction on the surface, a correction for the probability of excitation of a molecule should be made. Copyright

Temperature dependent solvent effects in photochemistry of 1-phenylpentan-1-ones

Temperature dependent solvent effects have been investigated on the Norrish Type II reaction of 1-phenylpentan-1-one and its p-methyl derivative. Efficiencies of the photoreaction were studied in terms of solvent polarity and base addition as a function of temperature. Such a small structure change as the p-methyl substitution in 1-phenylpentan-1-one altered the temperature dependent photoreactivity in presence of weak bases. The experimental results suggest that the hydrogen bonding between the Type II biradical intermediate OH group and the solvent is weaker for 1-(4-methylphenyl)pentan-1-one than that for 1-phenylpentan-1-one at 20°C but the interactions probably vanish in both cases at 80°C.

Photoreaction of valerophenone in aqueous solution

Kinetics and products of the photoreaction of the phenyl ketone valerophenone were investigated as a function of temperature, pH, and wavelength in aqueous solution. Under these conditions (-4M), the photoreactions are pseudo-first-order with respect to valerophenone concentration. Type II quantum yields for photoreaction were close to unity throughout the 290-330 nm spectral region and in the temperature range from 10 to 40 °C. The quantum yields for the photoproducts were 0.65 ± 0.04 for cleavage to acetophenone and propene and an overall yield of 0.32 ± 0.03 for cyclization to two cyclobutanols at 20 °C. A small amount of 1-phenylcyclopentanol (2% yield) also was formed. These photoreactions were quenchable by additions of the triplet quenchers sorbic alcohol or sorbic acid, and Stern-Volmer plots were linear up to at least 80% quenching of the photoreactions. On the basis of quenching studies with steady-state irradiations, the triplet lifetime of valerophenone at 20 °C was estimated to be 52 ns, 7 times longer than that observed in hydrocarbon solvents. Since the triplet lifetime is controlled by intramolecular hydrogen abstraction, these results indicate that the rate constant for H abstraction is significantly lowered in aqueous media. The slower H abstraction in aqueous solution is attributed to stabilization of the excited π,π* state by water and vibronic mixing and slight inversion of the reactive n,π* triplet and the unreactive π,π* triplet states. This interpretation also is supported by changes in the UV absorption spectra of phenyl ketones in water compared to organic solvents. Red shifts, compared to the polar organic solvent acetonitrile, were observed in the π-π* transitions of valerophenone and acetophenone, reflecting stabilization of the excited π,π* state by water. Other results indicated that the quantum yields for valerophenone photoreaction are pH-independent from pH 9 to pH 2 but decrease significantly below pH 2. The decrease at low pH is attributed to quenching of triplet reactivity via protonation of the excited triplet state. The use of valerophenone as a convenient actinometer for studies in water is discussed; its half-lives during midday exposure to summer sunlight in temperate latitudes are 30 min.

Role of water in intrazeolite photochemistry

The photochemical and photophysical behavior of several ketones included within Na X zeolites is dependent upon the adsorbed water within the zeolite. Results suggest that when the zeolite is dry (water free), the guest ketones reside within supercages and when the internal structure is filled with water the guest molecules are displaced to the external surface.

A study of norrish type II reactions of aryl alkyl ketones included within zeolites

The photochemical and photophysical behavior of a large number of phenyl alkanones included in zeolites has been investigated. The interior size and shape of the zeolites control the behavior of the triplet ketone as well as that of the 1,4-diradical generated by Norrish type II γ-hydrogen abstraction. A relationship between the size and shape of the reaction cavity and the extent of the restrictions on the triplet ketone and the diradical intermediate has been observed. A model based on the "reaction cavity" concept has been valuable in understanding the unique influence of the zeolite on the reaction course of the type II process.

A Comparsion between Zeolite-Solvent Slurry and Dry Solid Photolyses

The use of zeolite-solvent slurry as a convenient medium to carry out photoreactions is illustrated with four examples, namely Norrish type I reaction of dibenzyl ketones, Norrish type I and type II reactions of α-alkylbenzyl benzyl ketones, Norrish type II reaction of aryl alkyl ketones, and photodimerization of acenaphthylene.Solvent present within the supercages of zeolites X and Y provides constraint on the mobility of the included guest molecules.Such restrictions are reflected in the product distributions.The difference in the product distribution obtained between the zeolite-solvent slurry and a homogeneous solution is often higher than that between the dry powder zeolites and a homogeneous solution.

Organic reactions in liquid crystalline solvents. 10. Studies of the ordering and mobilities of simple alkanophenones in CCH-n liquid crystals by2H NMR spectroscopy and norrish II photoreactivity

The Norrish II reactions of butyrophenone (BP), valerophenone (VP), and hexanophenone (HP) have been carried out at 30°C as 0.6, 5.0, and 40 mol % solutions in the isotropic, smectic (crystal-B), and nematic liquid crystalline phases of trans,trans-4′ alkyl[1,1′-bicyclohexyl]-4-carbonitrile (CCH-n) liquid crystals. In each case, the distribution of fragmentation and stereoisomeric cyclobutanols from photolysis of the ketones in the nematic phase is similar to that obtained from photolysis in a model isotropic solvent. The product distribution from photolysis of 0.6 mol % BP in the crystal-B phase is also similar to that in the isotropic phase, but both the fragmentation/cyclization and trans/cis-cyclobutanol product ratios from photolysis of VP and HP are affected significantly by smectic liquid crystalline order. The magnitude of the effect correlates with the size of the γ-substituent and inversely with concentration. Deuterium NMR spectra of the a- and ring-deuterated analogues of the three ketones, along with those of acetophenone (AP) and propiophenone (PP), have been measured as a function of temperature and concentration in CCH-4. Homogeneous smectic solutions of α-deuterated AP, PP, and BP exhibit distinctive 2H NMR spectra with regular differences throughout the series, but VP and HP show no detectable spectral features within 100 kHz of center spectrum. These results afford a qualitative correlation of the motional behavior of the solutes in the smectic phase as a function of alkanoyl chain length, which parallels that manifested in Norrish II reactivity. The ring-deuterated derivatives of all five ketones in the smectic phase show spectra consistent with solubilization of the probe in a highly ordered, oriented environment. Order parameters for the five ketones in the nematic phase at 52°C have been calculated from the spectra of the ring-deuterated derivatives. Solubility limits of the ketones in the crystal-B phase of CCH-4 have been determined from the concentration dependence of the spectra of the ring-deuterated derivatives.

SOLID STATE REACTIVITY OF COMPLEX COMPOUNDS. THE NORRISH TYPE II REACTION IN CRYSTALLINE 1,1,6,6-TETRAPHENYLHEXA-2,4-DIYNE-1,6-DIOL AND IN SOLID p-ISOPROPYLCALIXARENE.

Below are presented the Norrish Type II reaction of butyrophenone (Bph) and valerophenone (Vph) in benzene, tert-butanol and as complex compounds with 1,1,6,6-tetraphenyl-2,4-diyne-1,6-diol 1 and p-isopropylcalixarene 2 in the solid state and in solution.Product distributions lead to conclusions about the factors influencing the course of the reactions in the solid state.