| Abstract: | The mechanistic and synthetic aspects of the addition reaction of thioxophosphorane sulfenyl bromide with ethyl vinyl ether were studied in detail by NMR techniques. It has been found that the regiospecific, primary product of the reaction, 1-bromo-1-ethoxy-2S(dialkoxythiophosphoryl)ethane I, is unstable and undergoes slow decomposition to give four compounds. The formation of thiophosphoryl derivatives, vinyl ethers II and III, aldehyde IV, and the symmetrical hemiacetal anhydride V, has been considered in terms of a carbocation intermediate. By choice of the appropriate reaction conditions, the aldehyde IV can be obtained in very high yield. |
