Photochemically, covalent cycloaddition products of flavoquinone and acetylenic enzyme inhibitors have been prepared and elucidated, which appear analogous to flavoprotein-inhibitor complexes (monoamine and lactate oxidase). The additions occur with inhibitors of general type H C = C — C H < at the C (4a )=N(5 ) azomethine grouping of oxidized flavin. The spectral properties of adducts and thei...

Synthetic access to regiodifferentiated meta-amino phenols is described. The strategy relies upon distinct deprotonation conditions to afford regioisomeric thermodynamic and kinetic dienes that undergo a tandem Diels-Alder and retro-Diels-Alder sequence with assorted acetylenic dienophiles to afford a range of aromatic products.

Two new acetylenic fatty acids (1, 2), a new triglyceride (3), along with eleven known compounds including 3-oxo-11alpha,12alpha-epoxyurs-13beta,28-olide (4) previously reported as a synthetic compound, have been isolated from the leaves of Hymenodictyon excelsum. The structural identification was established from spectroscopic data.

The effect of 1, l-diphenyl-2-propynyl cyclohexylcarbamate on hemagglutinin and hemolysin formation by mice in response to sheep red blood cells has been investigated. A single LDio dose of drug was administered at various times before or after immunization and the hemaggluti nin response was evaluated. With this dose the drug, de pending on time of administration in relation to primary immune ...

Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels-Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence ...

Two pairs of diastereoisomeric acetylenic norlignan compounds with PhCH(OR(1))CH(OR(2))CH(2)C triple bond CPh skeleta: (1R, 2R)-1-O-methylnyasicoside (1) and (1S, 2R)-1-O-methylnyasicoside (2), and (1R, 2R)-crassifogenin D (3) and (1S, 2R)- crassifogenin D (4), were isolated from the ethanolic extract of rhizomes of Curculigo crassifolia. Compounds 3 and 4 are new and their structures were eluc...

fecl3.6h2o was used as an efficient catalyst for the synthesis of highly functionalized piperidines via a one-pot five-component reaction of aromatic amines, aromatic aldehydes and β-keto esters in etoh at room temperature. the remarkable advantages offered by this method are good yields, simple procedure, short reaction times, no need to column chromatography and easy work-up. the structures o...