A facile route to the benzooxabicyclo[3.2.1]octane (2,3,4,5-tetrahydro-2,5-methano-1-benzoxepine) system: application to a short synthesis of filiformin
作者:Asok Nath、Ramanathapuram V. Venkateswaran
DOI:10.1039/c39930000281
日期:——
Photolytic ethylene addition to 3-methoxychromones 3a–cfurnished the 3-hydroxyoxetanes4a–c; reduction to the diols 5a–c followed by acid-catalysed rearrangement afforded the benzooxabicyclo[3.2.1]octanones 6a–cand bromination of 6c furnished7, which has previously been converted to filiformin 2.
Facile photolytic demethoxylation of 3-methoxychromones
作者:Pranab Mandal、Asok Nath、R.V Venkateswaran
DOI:10.1016/0040-4020(96)00356-0
日期:1996.6
Photolysis of 3-methoxychromones in methanol furnishes chromones through extrusion of the methoxy function. A conjugate addition of methanol followed by a double methoxy elimination has been proposed to account for the cleavage product.
A Facile, Expeditious Route to the Benzooxabicyclo[3.2.1]octane System. Application to a Short, High-Yield Synthesis of Filiformin
作者:Asok Nath、Jayati Mal、Ramanathapuram V. Venkateswaran
DOI:10.1021/jo952184j
日期:1996.1.1
sequence. Lithiumaluminumhydridereduction to the diol 15 followed by acid-catalyzed rearrangement produced benzooxabicyclooctanone (16), arising from exclusive external bond migration. Similarly, ethoxychromone (17) under the same sequence of reactions afforded the homologous bridged ketone 20. For the synthesis of filiformin (1), methoxychromone 24 on ethylene cycloaddition followed by reduction of resultant