- Stereoselective synthesis of 1 %26apos;,5 %26apos;,7 %26apos;,8 %26apos;-tetrahydro-2 %26apos; H,4 %26apos; H-dispiro[[1,3] dioxane-5,3 %26apos;-quinoline-6 %26apos;,5 %26apos;%26apos;-[1 %26apos;%26apos;,3 %26apos;%26apos;]dioxane]-4,4 %26apos;%26apos;,6,6 %26apos;%26apos;-tetrone derivatives in the presence of benzoic acid as an efficient catalyst via one-pot multicomponent reaction