Aryl 1-chloroalkyl sulfoxides as acyl anion equivalents:a new synthesis of vinyl sulfides,ketones,and diketones from aryl 1-chloroalkyl sulfoxides and#alpha#,#omega#-dichloro-#alpha#,#omega#-disulfinylalkanes

摘要

Treatment of aryl a-chloroalkyl sulfoxides, which were synthesized from aryl 1-ch1oroa~ky~ aulfoxides ‘oy alkylation with lodoalkanes, with trifluoroacetic anhydride and Nal in acetone at low temperature afforded vinyl sulfides in high yields. The vinyl sulfides were converted to ketones by hydrolysis with HCIO4 in refluxing I ,4-dioxane in good yields. In this procedure, the lithiated aryl 1-chioro-alkyl sulfoxides acted as acyl anion equivalents. The procedure was extended to a synthesis of a.s~-diketones starting from a,w-dichloro-a,o.~-disulfinylalkanes. The procedure was found to work well when the length of the carbon chain of the a,w-disulfinylalkanes is longer than four, and the yields of the diketones were found to be somewhat variable (60—80%).