Phenalen-1-one was obtained in considerable yield by reducing 3-hydroxyphenalen-1-one. Most of known preparation methods are not very practical, either because their yields are very poor or because their processes have many steps. This regioselective 1,2-reduction proceeded by the action of NaBH4 and various cations of rare-earth elements and metals. The yields of phenalen-1-one were examined as a function of typical lanthanoids, molar ratios of lanthanoid ions to 3-acetoxy-phenalen-1-one, and differing methods of protecting the hydroxyl group. Lanthanum chloride (LaCl3) gave the greatest yield (45.3%) of phenalen-1-one at molar ratios higher than a third, probably because La3+ ion is a hard acid and coordinates easily to a hard solvent such as methanol. Further, it has the largest ionic radius among all lanthanoid ions.
Dokunikhin,N.S.; Solodar',S.L., Journal of Organic Chemistry USSR (English Translation), 1968, vol. 4, p. 2089 - 2094
作者:Dokunikhin,N.S.、Solodar',S.L.
DOI:——
日期:——
Thermal Cyclization of 2-Acyl-1-azido-3-phenalenones to Phenaleno[1,2-c]isoxazol-7-ones
作者:Wolfgang Stadlbauer、Michaela Fischer
DOI:10.1002/jhet.5570350427
日期:1998.7
1-Azido-3-phenalenones 5 with acyl substituents in position 2, obtained by acylation and azidation of 1-hydroxy-3-phenalenones 1, cyclized by thermolysis to give phenaleno[1,2-c]isoxazol-7-ones 9. The thermolysis conditions were studied by differential scanning calorimetry.