Recep Ozen

The first generation and trapping of a five-membered ring allene: 2-dehydro-3a,4,5,6,6a-pentahydropentalene

Abstract 3-Bromo-3-fluorotricyclo[3.3.0.02,4]octane ( 8 ) was prepared by addition of bromofluorocarbene to bicyclo[3.2.0]hept-6-ene ( 5 ). Treatment of a solution of 8 in ether with MeLi in the presence of furan afforded the trapping product 11 . The formation of the trapping product is consistent with the first generation of a five-membered ring allene, namely, 2-dehydro-3a,4,5,6,6a-pentahydropentalene ( 4 ), a reactive intermediate.

Synthesis of 3,4-disubstituted furans via unsaturated cyclic peroxides arising by photooxygenation of 2,3-bis (bromomethyl)-1,3-butadiene and derived exocyclic dienes

Abstract The reaction of 2,3-bis (bromomethyl)-1,3-butadiene (3) with singlet oxygen resulted in the formation of a peroxide (4) which rearanged with CoTPP to bis(bromomethyl)furan. Zinc-induced debromination of cycloadducts which were obtained from the [2+4] Diels-Alder reactions of 3 with DMAD and benzyne gave exocyclic dienes 7 and 11 from which fused ring furans were prepared by photooxygenation followed by rearrangement. 4,5-Dimethylene-1,2-dioxane (14) was synthesized by zinc-induced debromination of 4. The cycloaddition reactions of 14 with MTAD, singlet oxygen and DMAD were studied.

Generation and trapping of a highly strained bicyclic allene: tricyclo[6.3.1.02,7]dodeca-2,4,6,9,10-pentaene

Abstract 10-Bromo-10-fluorotetracyclo[6.3.1.02,7.09,11]dodeca-2,4,6-triene ( 12 ) was prepared by addition of bromofluorocarbene to benzonorbornadiene ( 10 ). Treatment of a solution of 12 in ether with MeLi in the presence of furan or styrene afforded the trapping products 14 / 15 and 16 , respectively. The formation of these trapping products confirms the formation of the title cycloallene 1 as a reactive intermediate.

3-Carboxypyridinium trichloroacetatochromate (CPTCAC): as a mild and effective new reagent for the thiols to disulfides

A new chromium(VI) reagent, 3-carboxypyridinium trichloroacetatochromate (CPTCAC) was prepared by reacting 3-carboxypyridine (nicotinic acid) and trichloroacetic acid with CrO3 in water. This oxidising agent oxidised the thiols to disulfides selectivily and in very high yields.

Rearrangement of unsaturated cyclic peroxides obtained by photooxygenation of 2,3-dimethylene-7-oxabenzonorbornene and 2,3-dimethylene-1,4-etheno-1,2,3,4-tetrahydronaphthalene

Abstract Cobalt(II) tetraphenylporphyrin (CoTPP)-catalyzed rearrangement of peroxide 11 obtained by the photooxygenation of 5 gave a mixture of epoxides 15 (or 16) and 17. However, CoTPP-catalyzed rearrangement of peroxide 20 arising by photooxygenation of 2,3-dimethylene-1,4-etheno-1,2,3,4-tetrahydronaphthalane 6 gave 1,4-etheno-1,2,3,4-tetrahydronaphtho[b]-furan 21. The different behaviour of these endoperoxides 11 and 20 is discussed in terms of ring strain and the degree of the pyramidalization of the CC bond.

Chemistry and Alternative Usage of Missile Propellants Stored in Azerbaijan

The storage of liquid missile propellants Samine (mixture of xylidine and triethyl amine) and Isonite (isopropyl amine) present a great environmental problem in Azerbaijan. These compounds are no longer in use as propellants. In this paper we will discuss some chemical properties, production and alternative usage of these compounds in industry apart from being propellants and we will give some recommendations for alternative usage with respect to public and environmental safety.

Potassium fluoride/alumina mediated simple synthesis of Hantzsch 1, 4-dihydropyridines

A general and practical technique to achieve synthesis of 1,4-dihydropyridines in excellent yields has been investigated using potassium fluoride/alumina (KF/Al2O3) as a solid base. The ammonia was obtained either from thermal decomposition of ammonium acetate or by passing ammonia gases in the form of bubbled through hetereogenous reaction medium using an apparatus.

Diethyl 2,6-Dimethyl,4-(1,1,1-trichloromethyl)-1,4-dihydropyridine-3,5-dicarboxylate

In 1882, Hantzsch reported the first synthesis of dialkyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylates from a refluxing mixture of an aldehyde, a β-ketoester, and aqueous ammonium hydroxide in ethanol.[...]