Spiro[5.5]undeca-1,4,8-trien-3-ones are prepared by reacting a phenol having a free p-position with formaldehyde, a nitrogen compound selected from ammonia and primary and secondary amines, and a conjugated diene in an inert solvent at a temperature of at least about 190.degree. C.
Spiro[5.5]undeca-1,4,8-trien-3-ones是通过在惰性溶剂中以至少190°C的温度下,将具有自由p位的
苯酚与
甲醛、
氨和一级和二级胺中选择的氮化合物以及共轭二烯烃反应制备的。