25062-95-7

Upstream product

• 107-21-1 ethylene glycol 
• 134-81-6 benzil 
• 501-65-5 diphenyl acetylene 
• 100-52-7 benzaldehyde 
• 936-51-6 2-phenyl-1,3-dioxolane 
• 119-61-9 benzophenone 

Relevant academic research and scientific papers

Geminal Substituent Effects. VIII. Enthalpies of Formation od Acetals

The standard enthalpies of combustion ΔHoc(1 or c) of the α-phenyl-substituted acetals (1) and diacetals (2) were measured calorimetrically.The enthalpies of vaporisation or sublimation ΔHvap or ΔHsub of 1-2 were obtained from the temperature function of the vapor pressure measured in a flow system, and the standard enthalpies of formation are obtained thereof: ΔH0f (l or c) and ΔHof (g) (in kJ mol-1 for 1a= -308.40+/-0.52(1), -248.94+/-0.88; 1b= -343.48+/-0.72(1), -288.5+/-1.5; 1c= -267.4+/-1.3(1), -205.3+/-1.3; 1d = -343.8+/-2.1 (c), -261.9+/-2.2; 1e = -397.02+/-0.86 ( c), -311.3+/-1.2; 1f = -414.52+/-0.80 (1), -350.68+/-0.86; 2a = -564.8+/-2.4 (c), -467.1+/-2.5; 2b = -547.6+/-1.6 (c), -414.9+/-2.7; 2c = -717.1+/-7.5 (c), -587.0+/-8.0.The results are combined into values of two strain free group increments CHPh> = -59.7 and CPh, C> = -71.3 kJ mol-1; and compared to the aliphatic series of acetals.

Synthesis of monoprotected 1,4-diketones by photoinduced alkylation of enones with 2-substituted-1,3-dioxolanes

Photosensitized hydrogen abstraction from 2-alkyl-1,3-dioxolanes by triplet benzophenone gives the corresponding 1,3-dioxolan-2-yl radicals and these are trapped by α,β-unsatured ketones yielding monoprotected 1,4-diketones. With open chain ketones (3-buten-2-one and 4-penten-3-one) the yields are low and competitive pathways in part consume the radicals. With cyclic enones however, yields are good as tested with cyclopentenone, cyclohexenone and 4-hydroxy-cyclopentenone. More generally, this is a viable alternative for the synthesis of 1,4-diketones via radicals while the thermal initiation gives only low yield. The reaction cannot be extended to strongly stabilized radicals, such as the 2-phenyl-1,3-dioxolanyl radical.

Rotational isomerism and crystal structures of 2,2′-diphenyl-2,2′-bi-1,3-dithianyl and 2,2′-diphenyl-2,2′-bi-1,3-dioxolanyl

Dipole moments of the compounds 2,2′-diphenyl-2,2′-bi-1,3-dithianyl 1 and 2,2′-diphenyl-2,2′-bi-1,3-dioxolanyl 2 in carbon tetrachloride and benzene have been measured over a range of temperatures. The crystal and molecular structures of the compounds were determined by single-crystal X-ray diffraction methods. Analyses of the crystal structures and relative permittivity data show that the compounds exist in the trans conformation in the solid state and as rotameric mixtures in solution with a predominantly high trans population of 85% and 80% respectively at 25°C. The experimentally derived values of the energy difference between the gauche and trans rotamers and the gauche/trans population quotients were compared with the values predicted by molecular orbital calculations.

Oxidation of Diphenylacetylene by I7+ and I5+ Compounds

The oxidation of diphenylacetylene with H5IO6 in acetic acid affords benzil.In methanol the principal products are the monoketal and the diketal of benzil, depending upon water content.Similar products are formed in methanol when I2O5 is the oxidizing agent.The latter and the alkyne in ethylene glycol afford benzil and the corresponding diketal.Both systems appear to require the presence of iodine for effective action.