Nine substituted sulfonyl-stabilized phosphorus ylides were prepared by treating their intermediate ylide analogues with phenylmethanesulfonyl fluoride. The stoichiometric ratio of the reactants for each preparation needed to be adjusted according to the basicity of each ylide intermediate. The nine ylide compounds were then subjected to conventional (sealed- tube) gas-phase pyrolysis at 470 545 K. The pyrolytic reactions were homogeneous and ...