Yasushi Sanno

Studies on antianaphylactic agents—I : A facile synthesis of 4-oxo-4H-1-benzopyran-3-carboxaldehydes by Vilsmeier reagents

Abstract By the application of the Vilsmeier-Haack reaction to various o -hydroxyacetophenone derivatives, 4-oxo-4 H -1-benzopyran-3-carboxaldehydes were synthesized in one step. Their IR, NMR and mass spectra were studied. In the mass spectra characteristic fragmentation pathways were observed.

Chemical studies on Heliangine : A new sesquiterpene lactone isolated from the leaves of Helianthus tuberosus L

Abstract The structure of heliangine has been found to be I on the basis of its chemical studies.

Selective β-adrenoceptor activities of tetrahydronaphthalene derivatives

Abstract Alpha - and beta -adrenoceptor activities of a group of tetralin derivatives prepared as fixed analogs of isoproterenol, adrenaline and noradrenaline were evaluated in vitro assays. All of the present compounds showed strong direct β-stimulating activity fairly selective for tracheal muscle. Activity of a trans isomer about the C(1)-C(2) bond was ten times higher than that of the cis isomer. None of the compounds tested had any practical α-adrenoceptor activity. Structure-activity interrelationships between the present series of compounds and some known adrenergic agonists are discussed.

Studies on antianaphylactic agents—III : A novel conversion reaction of 4-oxo-4H-1-benzopyran-3-carboxaldehydes to 3-halogenochromones

Abstract 4-Oxo-4H-1-benzopyran-3-carboxaldehydes in acetic acid react with sodium hypochlorite (aqueous solution) to yield 3-chlorochromones. The reaction of sodium hypobromite with 1 yields 3-bromochromone 15 and other compounds depending on the conditions. Under the normal laboratory lighting hydroxyacetophenone 14, 15 and hydroxychromanone 16 were obtained, whereas 15 and acetoxychromanone 17 were produced by the reaction in the dark. The addition-elimination mechanism described is the most likely in these reactions.