1-oxaspiro[5.5]undec-7-ene systems have been prepared by utilizing Amberlyst-15-catalyzed intramolecular SN2′ oxaspirocyclizations of secondary allylic alcohols under mild reaction conditions in quantitative yields. This oxaspirocyclization was applied to the total synthesis of theaspirane and theaspirone from β-ionone in five steps.
各种取代的1-氧杂螺[4.4]非6-烯,1-氧杂螺[4.5] dec-6-烯,6-氧杂螺[4.5] dec-1-烯和1-氧杂螺[5.5] undec-7-通过在温和的反应条件下以定量收率利用仲烯丙基醇的Amberlyst-15催化的分子内S N 2'氧代螺环化反应制备烯键体系。该氧杂螺环化以五个步骤应用于从
β-紫罗兰酮的茶皮螺烷和茶皮螺酮的全合成中。