The Nitric Acid Oxidation of 2,5-Diphenylfurans to Cis Unsaturated 1,4-Diketones

Abstract

procedure yielded phenylglyoxime which, after two recrystallizations from chloroform, melted at 168°alone or mixed with authentic phenylglyoxime prepared from , -dibromoacetophenone. This shows the oil to be , -dichloroacetophenone and the dimethoxy compound to be l-phenyl-l,l-dimethoxy-2,2-dichloroethane. In accord with this structure the dimethoxy compound is stable toward potassium hydroxide in methyl alcohol solution.By refluxing a solution of 1 g. of pure compound and 3 g. of potassium hydroxide in 15 cc. of absolute methyl alcohol for four hours, evaporating the solvent and extracting the potassium hydroxide from the residue with cold distilled water, 85% of the pure dimethoxy compound was recovered.Summary Phenylacetylene reacts rapidly with chlorine and absolute methyl alcohol to produce about a 70% yield of l-phenyl-l,l-dimethoxy-2,2-dichloroethane of m. p. 66°, which is evidently formed by the addition of two molecules of methyl hypochlorite to the triple bond of the unsaturated compound.

Stereoselective Synthesis of cis-2-Ene-1,4-diones via Aerobic Oxidation of Substituted Furans Catalyzed by ABNO/HNO3

“…Accordingly, the development of efficient, practical, and high selective oxidation methods of furan derivatives has attracted considerable attention. Numerous stoichiometric metal oxidants and organic oxidants have been explored to achieve these transformations, which include metal oxidants [Ce­(NO 3 ) 6 (NH 4 ) 2 , MnO 2 , and Pb­(OAc) 4 ] peroxides [ m -CPBA, dimethyl dioxirane, CH 3 CO 3 H, MMPP, Fe 2+ /H 2 O 2 , UHP/MTO, Mo­(CO) 6 /TBHP, t BuOOH/Ti­(IV), and oxone] and other oxidants (SeO 2 , HNO 3 /AcOH, NaH 2 PO 4 /NaClO 2 , DDQ, Br 2 , and Selectfluor). Molecular oxygen represents the most inexpensive, readily available, and environmentally benign oxidant; therefore, aerobic oxidation methods offer a compelling alternative .…”

Reduction of cis- and trans-1,2-dibenzoylethylene and cis-.ALPHA.,.BETA.-dibenzoylstyrene with a combination of aluminum isopropoxide and aluminum chloride.

“…Chem. Soc., 75, 393(1953) tc E. In the reduction of 1, 2-dibenzoylethylene [l a, b] with aluminum isopropoxide, the addition of aluminum chloride increased the yields of furan derivatives [5], [6 ] or [7]. The cis-isomer was isomerized to trans-under the reduction conditions.…”

“…The structures of products [6], [7], [9] and [10] were established on the basis of spectral data (Table 5).…”