T. Tomoyoshi Takahashi

A novel one-pot synthesis of 3-acetyl- and 3-benzoylisoxazole derivatives using ammonium cerium nitrate (CAN)

Abstract The reaction of dipolarophiles (several alkenes and alkynes) with ammonium cerium(IV) nitrate ((NH 4 ) 2 Ce(NO 3 ) 6 , CAN(IV)) in acetone under reflux gave 3-acetylisoxazole derivatives. In the case of acetophenone, 3-benzoylisoxazole derivatives were obtained. Moreover, it was found that yields of isoxazole derivatives were improved using ammonium cerium(III) nitrate tetrahydrate ((NH 4 ) 2 Ce(NO 3 ) 5 ·4H 2 O, CAN(III))–formic acid.

Synthesis of α,β-unsaturated ketone from α-iodo ketone using photoirradiation

Abstract Irradiation of α-iodo ketone in hexane under a nitrogen atmosphere with a high-pressure mercury lamp (λ>300nm) at room temperature afforded the corresponding α,β-unsaturated ketones in good yield. This reaction affords a new, clean and convenient synthetic method for the α,β-unsaturated ketone.

Esterification of alkene with cerium(IV) sulfate in carboxylic acid

Reaction of alkenes [cyclohexene (1), cycloheptene (2), cyclooctene (3), 1-heptene (4), 1-octene (5), styrene (6), 1,7-octadiene (7), indene (8), and 1,2-dihydronaphthalene (9)] with cerium(IV) sulfate (CS) in carboxylic acids [formic acid, acetic acid, and propionic acid] readily yielded the corresponding carboxylic esters. This addition reaction follows the Markovnikov rule. This reaction provides a new simple method for preparing carboxylic esters from alkenes. It was also found that this method is useful for formylation.

Novel self-coupling reaction of cyclic ketones under a high-pressure mercury lamp

Abstract A novel self-coupling reaction in alcohol or hexane-water of cycloalkanone (cycloheptanone, cyclooctanone, and cyclododecanone) with irradiation under a high-pressure mercury lamp yielded the corresponding pinacol-type compound in good yields. In the case of cyclohexanone, 2-methyl-, 2-phenyl-, 4-methylcyclohexanone, 5α- and 5β-cholestan-3-one, the pinacol derivatives were not obtained and the dimethyl acetals were given.