Topic
Benzopyran
About: Benzopyran is a(n) research topic. Over the lifetime, 1889 publication(s) have been published within this topic receiving 15235 citation(s).
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TL;DR: The first direct organocatalytic asymmetric domino oxa-Michael/aldol condensation reaction is presented, which proceeds with high chemo- and enantioselectivities to give the corresponding chromene-3-carbaldehyde derivatives in high yields and with ee values of 83-98%.
Abstract: Catalytic enantioselective domino oxa-Michael/aldol condensations: asymmetric synthesis of benzopyran derivatives : -
186 citations
Abstract: Acid catalysed condensations of various 2 substituted 1,3-oxazinanes 3 and 1,3-oxazolidines 4 with cyclic carbon nucleophiles viz. 5,5-dimethyl-1,3-cyclohexanedione and 1,3-cyclohexanedione furnish xanthene derivatives, whereas a Knoevenagel reaction proceeds with acyclic nucleophiles. In case of 4b and 4c, a unique synthesis of functionalised α-tetralones has emerged. Reactions of mixtures of cyclic and acyclic carbon nucleophiles with 3 provide some functionalised and partially reduced benzopyran derivatives.
159 citations
149 citations
TL;DR: Three unique pyrano-1,6-dione derivatives and a new furo[3,2-c]pyran-4-one, named phelligridins C-F (2-5), together with hispolon (8), (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (9), 4-hydroxybenzaldehyde, protocatechualdehyde,
Abstract: Three unique pyrano[4,3-c][2]benzopyran-1,6-dione derivatives and a new furo[3,2-c]pyran-4-one, named phelligridins C−F (2−5), together with hispolon (8), (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (9), 4-hydroxybenzaldehyde, protocatechualdehyde, syringic acid, protocatechuic acid, caffeic acid, isoergosterone, and octadecyl ferulate were isolated and identified from the ethanolic extract of Phellinus igniarius. Their structures were determined by spectroscopic methods including IR, MS, and 1D and 2D NMR experiments. The structures of the new compounds were characterized as 3-(4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (2), 3-(3,4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (3), 8,9-dihydroxy-3-{5‘,6‘-dihydroxy-5‘ ‘-methyl-3‘ ‘-oxo-spiro[fural-2‘ ‘(3‘ ‘H),1‘-indene]-2‘-yl}-1H,6H-pyrano[4,3-c][2]benzopyran-1,6-dione (4), and (3Z)-3-(3,4-dihydroxybenzylidene)-6-(3,4-dihydroxystyryl)-2,3-dihydro-2-methoxy-2-(2-oxo-propyl)furo[3,2-c]pyran-4-one (5), respectively. Some compound...
148 citations
Patent•
18 Apr 1998Abstract: A class of benzopyran derivatives is described for use in treating cyclooxygenase-2 mediated disorders. Compounds of particular interest are defined by Formula (I'), wherein X, A?1, A2, A3, A4?, R, R', R?1 and R2? are as described in the specification.
148 citations