Abstract— Photolysis at 254 nm of alkyl benzohydroxamates [C, H, CONHOR: R = CH3 H2CH3 CH(CH3)2, CH2C6H5 CH(CH3)C2H5 CH(CH3)‐n‐C6H13] in acetonitrile or hydrocarbon solvents gives benzamide. These reactions can be sensitized by benzophenone (at ca. 350 nm) and are quenched by cis‐piperylene. Racemization occurred when 2‐octyl (+)‐benzohydroxamate was irradiated in cyclohexane. These results are consistent with a mechanism involving a triplet biradical. Photolysis of phenyl benzohydroxamate [C6H5CONHOC6H5] and benzyl N‐methylbenzohydroxamate [C6H5CON‐(CH3)OCH2Q6H5] cannot be quenched with ris‐piperylene and appear to be singlet reactions.

The 3-and 4-aminophthalimidoacetic acids and their methyl esters have been synthesized by hydrogenation of the corresponding nitro compounds, hnd the ultraviolet absorption spectra of these and of the aminophthalimides have been determined. The aminophthalimide moieties have absorption maxima at 385-389 µ for the 3-isomer and 372-375 µ for the 4-isomer, but show a substantial hypsochromic shift under basic conditions. The results are discussed in terms of structures of substituted phthalimides and the reactions of the imide group with aqueous base.

No abstract

No abstract

Pauson-Khand Reaction of Allenic Hydrocarbons: Synthesis of 4-Alkylidenecyclopentenones. -A comprehensive study of the reaction of in situ generated dicobalthexacarbonyl complexes of disubstituted alkynes, terminal alkynes, or acetylene with a variety of mono-and disubstituted allenes is presented yielding mainly the title cyclopentenones. The regio-and stereoselectivities depend mainly on the substitution pattern of both the alkyne and the allenic moiety. -(ANTRAS, F.; LAURENT, S.; AHMAR, M.; CHERMETTE, H.; CAZES*, B.; Eur.