Preparation of 1,1,1,3,3-pentafluoropropane (HFC-245fa) by using a SbF5-attached catalyst

In this report, a simple process for preparing HFC-245fa through the reaction of 1,1,1,3,3-pentachloropropane (PCP) and anhydrous HF via two-step vapor-phase catalytic fluorination is described. The antimony pentafluoride catalyst was supported on inert porous materials to improve the catalytic activity. The resulting process catalyst not only exhibited high catalytic activity and excellent thermo-stability, but also improved the performance of SbF₅, in terms of hygroscopicity and corrosion.     

Synthesis and Odor Evaluation of Stereoisomers of Imine Derivatives in Roasted Spotted Shrimp

All possible stereoisomers of imine derivatives 1 – 4 , which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood.     

Palladium catalyzed synthesis of tertiary allylamines. Utilization of α-nitro olefins as allylic nitro compounds

Reaction of α-nitro olefins with secondary amines in the presence of palladium(O) catalyst affords allylic amines.     

Diastereo- and Enantiocontrolled Synthesis of (–)-Allosedamine via Cycloaddition of a Chiral Nitrone

The piperidine alkaloid (–)-allosedamine ( 1 ) has been synthesized, in 21% overall yield, in nine steps starting from the formyl-ester 4 . The synthesis features the reaction cascade 7 → 3 → 2 , involving asymmetric electrophilic enolate hydroxyamination, hydroxylamine/aldehyde condensation, and nitrone/styrene cycloaddition, as well as the reductive N/O cleavage-decyanation 12 → 1 .     

Three new quassinoids,ailantinol E,F, and G,from Ailanthus altissima

Three new quassinoids, ailantinol E (1), ailantinol F (2), and ailantinol G (3), and related compounds were isolated from Ailanthus altissima grown in Taiwan. Their structures were elucidated from spectral evidence. Each new quassinoid was evaluated for its antitumor promoting effects against Epstein-Barr virus early antigen activation introduced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. The new quassinoids were found to show potent activity without showing any cytotoxicity. The screening for inhibitors against nitric oxide donor action was also conducted using the new quassinoids and some standard samples.     

Measurement of the product ion ratio N4+/N3+ in the radiolysis of nitrogen

The ratio of N₄⁺ to N₃⁺ formed in the radiolysis of gaseous nitrogen has been measured to be 4.7 ± 0.4 using a time-resolved atmospheric pressure ionization mass spectrometer. The limit of error has been evaluated from the ion mass discrimination of the apparatus.     

Studies of the polymerization of diallyl compounds. XXII. Polymerization of diallyl oxalate in the evolution of carbon dioxide at elevated temperatures

The polymerization of diallyl oxalate was conducted in the presence of radical initiators at a high temperature range of 80–180°C; a large decrease in degree of polymerization, an increase in residual unsaturation of the resulting polymer, and the evolution of carbon dioxide were observed with the elevation of temperature. These findings were reasonably interpreted by considering the dismutation of the uncyclized growing radical to yield the allyl radical, carbon dioxide, and polymer carrying a terminal double bond. The kinetics of the polymerization of diallyl oxalate in the evolution of carbon dioxide at elevated temperatures were also discussed in detail.     

The synthesis of hexahydrooxoepithiopyridinedicarboximides by the reaction of thioamides with N-substituted maleimides

The synthesis of hexahydrooxoepithiopyridinedicarboxyimide (5: X₂ = N-Ph) by the reaction of thioamides 1 with N-substituted maleimide ( 2a ) was examined. The reaction of primary thioamides, such as thiobenzamide and p-toluthioamide with N-phenylmaleimide gives compounds 5 together with corresponding 4-hydroxy-1,3-thiazoles 4 . However, a similar reaction of secondary thioamides, such as N-methylthioacetamide, thiobenzanilide, with N-phenylmaleimide did not provide compounds 5 without addition of acid. The reaction pathway and the configuration of 5 were also investigated.     

1,3-Dipolar cycloaddition reaction of phenanthridinium N-imines and N-benzoylimine with acetylenic compounds

N-Aminophenanthridinium salt reacted with dimethyl acetylenedicarboxylate in the presence of potassium carbonate to give a 3,3a-dihydropyrazolo[1,5-f]phenanthridine but with mono-substituted acetylenes (ethyl propiolate and benzoylacetylene) it produced aromatized pyrazolo-[1,5-f]phenanthridines (XII and XIII). The reaction of the N-benzoylimine with di-substituted acetylenes (dimethyl acetylenedicarboxylate and methyl phenylpropiolate) and mono-substituted acetylenes (ethyl propiolate and benzoylacetylene) yielded 1,3a-dihydropyrazolo[1,5-f]phenanthridines and the aromatized products (XII and XIII), respectively.     

Synthesis of (±)-ascochlorin,an antiviral antibiotic

(±)-Ascochlorin, 5-chloro-2, 4-dihydroxy-6-methyl-3-[(2$\text{E}$, 4$\text{E}$)-5-(1,2,6-trimethyl-3-oxocyclohexyl)3-methyl-3,4-pentadienyl] benzaldehyde, was synthesized in 14 steps from (±)-3,4-dimethyl-2-cyclohexenone.