Contrary to the reports in the patent literature, the title compounds could not be synthesized via the Mannich reaction with alkyl a-(alkylsulfony1) acetate RS02CH2COOR'(R= R'= CH3 or other alkyl groups). A synthetic sequence which utilizes selenoxide elimination proved to be the most successful for obtaining the title compounds in high yields. The alkyl a- (alkylsulfony1) acrylates polymerize much more readily than the corresponding ...