A simple radical addition-elimination route to geometrically pure (E)-alkene and chromanone derivatives via beta-nitrostyrene.
Various geometrically pure (E)-beta-alkyl-styrenes have been synthesized by the radical NO(2) substitution of alkyl moieties generated via hydrogen abstraction followed by decarbonylation from aliphatic aldehydes. These reactions, which involve a high chemical selectivity and regioselectivity constitute a new route to (E)-beta-alkylstyrenes. Both aliphatic and aromatic aldehydes can be used in this novel reaction. When 2-allyloxybenzaldehyde was used, the benzoyl radical added directly to the double bond without decarbonylation to give the 3-cinnamylchroman-4-one. This unique difference between aliphatic and aromatic aldehydes represents a simple route for the synthesis of biologically important chromanones.
Jang
Yeong-Jiunn
YJ
Department of Chemistry, National Taiwan Normal University 88, Sec. 4, Tingchow Road, Taipei, Taiwan 116, ROC.
Yan
Ming-Chung
MC
Lin
Yung-Feng
YF
Yao
Ching-Fa
CF