Eco-friendly synthesis of fused pyrano[2,3-b]pyrans via ammonium acetate-mediated formal oxa-[3 + 3]cycloaddition of 4H-chromene-3-carbaldehydes and cyclic 1,3-dicarbonyl compounds

Abstract

We report the eco-friendly synthesis of fused pyrano[2,3-b]pyrans via ammonium acetate-mediated formal oxa-[3 + 3]-cycloaddition of 4H-chromene-3-carbaldehydes and cyclic 1,3-dicarbonyl compounds.

The Construction of Polycyclic Pyridones via Ring-Opening Transformations of 3-hydroxy-3,4-dihydropyrido[2,1-c][1,4]oxazine-1,8-diones

“…Taking into account the effect of AcOH, we tried to use AcONH 4 as a bifunctional catalyst [ 31 , 32 ] for this process. To our delight, the product was obtained in a good yield (69%) under reflux for 12 h (TLC monitoring) ( Table 2 ).…”

Efficient and stereoselective synthesis of sugar fused pyrano[3,2-c]pyranones as anticancer agents

“…16,17 Moreover, this structure constituted building blocks for many natural products found in plants, [18][19][20] where some of them showed high potency towards biological activities. 21 For instance, triptiliospinocoumarin (A), 22 vismiaguian A (B), 23 pyripyropene T (C), 24 were found naturally while synthetic compound D 25 was cytotoxic to neuroblastoma and melanoma cells. The tricyclic E 26 -F 17 might be utilised for the prevention and treatment of neurodegenerative diseases, such as Alzheimer's disease.…”

“…Compounds G-J were strong inhibitors of acetylcholinesterase activity, DNA synthesis, and leukemic cell growth. 21,27 Recently, sugar fused pyrano-pyranone derivative K 28,29 has been proved to be an antiproliferative agent i.e. against breast and liver cancer cell (Fig.…”

An Efficient Carbonized Sugar Catalyzed Entry to 7,8-dihydro-2<i>H</i>-Chromen-5(6<i>H</i>)-ones

“…1,3-Dicarbonyl compounds are versatile synthons for the incorporation of electrophilic and nucleophilic units [26][27][28]. Further, these derivatives can be converted to form a 2H-pyran motif by condensation with α, β-unsaturated aldehydes followed by [3+3] cycloaddition [29][30][31]. This approach allows the facile generation of cyclic rings with new stereogenic centers.…”