Photochemical deoxygenation of an α-ketol: the dihydroflavonol–flavanone conversion
Abstract
Irradiation of optically pure 2,3-trans-3-hydroxyflavanones in anhydrous ethyl acetate leads directly to free phenolic flavanone analogues with complete retention of configuration at C(2). Similarly their methyl ethers give the corresponding flavanones and flavones. The reaction represents the photochemical equivalent of a reduction under Clemmensen conditions.