A Convenient Synthesis of Substituted Spiro[5.5]Undecanes Using Lewis Acid Catalysts

Abstract

A one-pot synthesis of 3, 3-Dimethyl-7, 11-diphenyl-spiro [5, 5] undecane-1, 5, 9-triones 4a-c has been achieved by the application of Michael reaction between dimedone (5,5-dimethylcyclohexane-1,3-dione) 1 and trans,trans diarylideneacetones [1,5-diaryl-1,4- pentadien-3-ones] 2a-c (a. Ar = C₆H_5-, b. Ar = 2-Cl-C₆H_4-, c. Ar = 2- CH₃O- C₆H₄) using Lewis acid catalysts.