A Novel Synthesis of 4H-Chromen-4-ones via Intramolecular Wittig Reaction

3-(4-Nitro­benz­yl)-4H-chromen-4-one

In the title compound, C16H11NO4, the dihedral angle between the ten-membered chromen-4-one ring system (r.m.s. deviation = 0.0095 Å) and the benzene ring is 86.16 (5)°. In the crystal, mol-ecules are linked into a three-dimensional network by weak C-H⋯O hydrogen bonds. The crystal studied was a non-merohedral twin, with the minor twin component refining to 0.093 (1).

H 08094 . Intramolecular Wittig Reaction : A New Synthesis of ( S ) - Pyrrolam A

Synthesis of functionalised 4H-quinolizin-4-ones via tandem Horner-Wadsworth-Emmons olefination/cyclisation.

4H-Quinolizin-4-ones are a unique class of heterocycle with valuable physicochemical properties and which are emerging as key pharmacophores for a range of biological targets. A tandem Horner-Wadsworth-Emmons olefination/cyclisation method has been developed to allow facile access to substituted 4H-quinolizin-4-ones encoded with a range of functional groups.

3-(3-Nitro­benz­yl)-4H-chromen-4-one

In the title compound, C16H11NO4, the dihedral angle between the 10-membered coplanar chromone ring system and the benzene ring is 77.83 (3)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.

3-Methyl-4H-chromen-4-one

In the title chromenone derivative, C(10)H(8)O(2), the two fused six-membered rings are coplanar, with a mean deviation of 0.0261 (1) Å from the plane through the non-H atoms of the rings. The carbonyl and methyl substituents of the pyran ring also lie close to that plane, with the O and C atoms deviating by 0.0557 (1) and 0.1405 (1) Å, respectively. In the crystal, weak C-H⋯O contacts form cha...