Baker's yeast catalysed enantioselective reduction of chroman-4-ones

1119-112

A facile synthesis of ethyl 2-methyl-5-oxo-5H-[1]benzopyrano[3,4-c]pyridine-carboxylates

686-68

A facile synthesis of 2-[4'-(2', 6' -dimethyl-3',5' –dicarbethoxy-1’,4'-dihydropyridyl)]chromones

965-96

A new synthesis of heterocyclic compounds with 1,5-benzodioxapine, 1,5- benzodiazepine, 1,5-benzothiazepine ring systems

34-3

Synthesis of ethyl 4-methyl-2, 10-dioxo-7,10-dihydro-2H-[1]pyrano-[2,3-f]quinoline-9-carboxylate from 7-amino-4-methylcoumarin

728-73

A facile synthesis of 2-(2'-vinylthiophene)chromones by the modified Baker-Venkataraman tansformation

579-58

A facile synthesis of 2-(2'-thienyl/2'-furyl)- and 2-o-tolyl-chromones by phase transfer catalysis method

847-85

Synthesis of 2,3-<i style="">trans</i>-3,4-<i style="">trans</i>-2-aryl-3-alkyl/aryl chroman-4-ols

618-621-Alkyl chalcones 3a-d on acid catalyzed cyclization give a mixture of (±) trans and (±) cis 2-aryl-3-alkylchroman-4-ones. cis 4a-d are converted to trans 5a-d by epimerization with dil. alkali. a-Aryl chalcones 3e-h on acid catalyzed cyclization give (±) trans 2,3-diaryl-chroman-4-ones 5e-h. On NaBH4 reduction 5a-h give (±) 2,3-trans-3,4-trans-2-aryl-3-alkyl/aryl- chroman-4-ols 6a-h

<span style="font-size:14.0pt;font-family:"Times New Roman";color:#090909;mso-bidi-font-weight: bold" lang="EN-IN">A facile <span style="font-size:14.0pt;font-family: "Times New Roman";color:#1B1B1B;mso-bidi-font-weight:bold" lang="EN-IN">synthesis of <span style="font-size:14.0pt;font-family:"Times New Roman";color:#090909; mso-bidi-font-weight:bold" lang="EN-IN">7,8/6,7 <span style="font-size: 14.0pt;font-family:"Times New Roman";color:#1B1B1B;mso-bidi-font-weight:bold" lang="EN-IN">fused <span style="font-size:14.0pt;font-family:"Times New Roman"; color:#090909;mso-bidi-font-weight:bold" lang="EN-IN">pyrano[<i><span style="font-size:14.0pt;font-family:Arial;color:#1B1B1B;mso-bidi-font-weight: bold" lang="EN-IN">4,3-b</span></i><span style="font-size:14.0pt;font-family: Arial;color:#1B1B1B;mso-bidi-font-weight:bold;mso-bidi-font-style:italic" lang="EN-IN">]<i> </i><span style="font-size:14.0pt;font-family:"Times New Roman";color:#090909; mso-bidi-font-weight:bold" lang="EN-IN">pyridinochromones <span style="font-size:14.0pt;font-family:"Times New Roman";color:#1B1B1B;mso-bidi-font-weight: bold" lang="EN-IN">and <span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#1B1B1B;mso-ansi-language:EN-IN; mso-fareast-language:EN-US;mso-bidi-language:HI;mso-bidi-font-weight:bold" lang="EN-IN">evaluation of antibacterial activity</span></span></span></span></span></span></span></span></span>

610-6137-Hydroxy-8/6-formyl chromones 2a-d on reaction with ethyl 3-aminocrotonate in acetic acid medium yield 7,8/6,7 fused pyrano[4,3-b]pyridino chromones 3a-d quantitatively.</span

Synthesis of angular furano - or pyrano-fused coumarins from natural scopoletin

858-862Starling from natural coumarin, scopoletin, the syntheses of 8-methyl-6-methoxy l-2H-furo(2 , 3-h)[1]benzopyran-2-one 4, 10-dihydro-9-hydroxy-6-methoxy-2H, 8H-benzo[1, 2-b; 3, 4-b] dipyran-2-one 7, 8-hydroxy-6-methoxy-2H, 8H-benzo[1, 2-b;3,4-b]dipyran-2-one 8 and 6-methoxy-2H, 9H-benzo [1, 2-b;3,4-b]dipyran-2, 8-dione 9 have been reported