In
organic chemistry several methods exist for the synthesis of flavones: •
Allan–Robinson reaction •
Auwers synthesis •
Baker–Venkataraman rearrangement •
Algar–Flynn–Oyamada reaction Another method is the dehydrative cyclization of certain 1,3-diaryl diketones.
Wessely–Moser rearrangement The
Wessely–Moser rearrangement (1930) has been an important tool in structure elucidation of flavonoids. It involves the conversion of 5,7,8-trimethoxyflavone into 5,6,7-trihydroxyflavone on hydrolysis of the
methoxy groups to
phenol groups. It also has synthetic potential for example: This
rearrangement reaction takes place in several steps:
A ring opening to the
diketone,
B bond rotation with formation of a favorable
acetylacetone-like phenyl-ketone interaction and
C hydrolysis of two methoxy groups and ring closure. == Common flavones ==