thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5hdibenzo-[a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. thefirst-order constants at various temperatures for the rearrangement process were evaluated from theabsorption time data. the activation parameters for this rearrangement were obtained from the...

microstructural investigation of low molecular weight 1,4-polybutadiene (1,4-pbd) was studied by 1h and 13c nuclear magnetic resonance spectroscopy (nmr). the isomer contents of 1,4-cis, 1,4-trans and 1,2- vinyl in polybutadiene microstructure were determined. the number average molecular weight for low molecular weight polybutadiene was measured by nmr techniques and comparison was made with g...

Thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5Hdibenzo-[a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. Thefirst-order constants at various temperatures for the rearrangement process were evaluated from theabsorption time data. The activation parameters for this rearrangement were obtained from the...

Thermal rearrangement of propargyl naphthyl ethers produced naphthopyrans. In the presence of sodium methoxide, propargyl naphthyl ethers were converted easily to naphthofurans and naphthodifurans in good yields

tert-Butylsulfinamides are unstable above room temperature, and in chlorinated solvents they undergo rearrangement to form the more stable N-(tert-butylthio)-tert-butylsulfonamide.

Thermal rearrangement of spirans (14) and (31) yields the xanthones (16,34) and diphenylrnethane (15, 32), respectively. The structure for xanthone (16), isolated from thermolysis, has been established by reduction to xanthene (20) followed by reoxidation to give xanthone (16). Alternatively, methylation of the diphenylmethane (15) followed by heating with selenium dioxide also yields xant...

Fe3O4 nanoparticles were employment as an efficient and magnetically separable Nano catalyst for the synthesis of amides via one-pot Beckmann rearrangement of ketones under solvent-free conditions. Various secondary amides were synthesized by this method in moderate to good yields. The catalyst showed high thermal stability and was recovered and reused at least five times without any considerab...

An asymmetric Claisen rearrangement using Oppolzer’s camphorsultam was developed. Under thermal conditions, a geraniol-derived substrate underwent the rearrangement with good stereoselectivity. The absolute configuration of the newly formed all-carbon quaternary stereocenter was confirmed by the total synthesis of (+)-bakuchiol from the rearrangement product.