Topic
Benzopyrans
About: Benzopyrans is a research topic. Over the lifetime, 694 publications have been published within this topic receiving 8830 citations.
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14 citations
TL;DR: The enamine (2) as discussed by the authors is a mixture of benzopyranone and dimethylformamide dimethyl acetal and on treatment with ammonia and hydroxylamine gives the fused pyridine 2-oxide (10), pyridinioacetamidate (11), and azepine (20), respectively.
Abstract: The enamine (2), prepared from the title benzopyranone (1; R2= H, Me, and Ph) and dimethylformamide dimethyl acetal, on treatment with ammonia and hydroxylamine gives the fused pyridine (5) and pyridine 2-oxide (10), respectively. Hydrazine, phenylhydrazine, and guanidine undergo initial 1,6-addition to the enamine (2) ultimately giving the pyrazoles (14) and (15), and the pyrimidine (17), respectively. The pyridinioacetamidate (11), prepared from the enamine (2; R2= Me and Ph) and acetohydrazide, thermolyses to the fused pyridine (5). A refluxing ethanolic solution of the enamine (2; R2= Me and Ph) with ethyl glycinate forms the ester (18) which on treatment with ethanolic sodium ethoxide produces the azepine (20).
14 citations
TL;DR: Evidence is provided that benzopyrans 7a-h may be operating via an alternative mechanism than ATP-sensitive K(+) channel activity, which is different from that of K(ATP) channel activity.
14 citations
TL;DR: The indole alkaloid echinuline and the anthraquinone fiscione, both unprecedented for the genus Lentinus, were isolated from the mycelium of the fungus.
Abstract: The basidiomycete Lentinus strigellus was cultivated in three different culture media and the secondary metabolites produced under different culture conditions were isolated and identified. When cultivated in a liquid medium with peptone, L. strigellus afforded the benzopyrans, 2,2-dimethyl-6-methoxychroman-4-one, 4-hydroxy-2,2-dimethyl-6-methoxychromane and (3R,4S)-3,4-dihydroxy-2,2-dimethyl-6-methoxychromane. The indole alkaloid echinuline and the anthraquinone fiscione, both unprecedented for the genus Lentinus, were isolated from the mycelium of the fungus. When cultured in Czapek medium enriched with potato broth, the fungus afforded the same benzopyrans except (3S,4S)-3,4-dihydroxy-2,2-dimethyl-6-methoxychromane. Panepoxydone and isopanepoxydone were also isolated when the microorganism was grown in Czapek medium.
14 citations
TL;DR: The evidence leading to the assignment of the relative stereochemistry to the tetramethyl octahydro-2H-1-benzopyrans is presented in this article.
Abstract: Edulan I and 11, two important trace components of the juice of passionfruit Passiflora edulis (Sims), were shown by micro-reaction g.l.c., by micro-spectrometry (m.s., N.M.R., i.r. and u.v.) and by com- parison with synthetic products to be the epimeric 2,5,5,8a- tetramethyl-3,5,6,8a-tetrahydro-2H-1-benzopyrans (8a) and (8b). The relative configurations of these isomers were established by their con- version into the stereoisomeric 2,5,5,8a-tetramethyl-3,4,4a,5,6,7,8,8a- octahydro-2H-1-benzopyrans (6a,b) and (6c,d) respectively. The evidence leading to the assignment of the relative stereochemistry to the tetramethyloctahydrobenzopyrans is presented.
13 citations