It is reported that a variety of trimethylsilyl enol ethers which are not ketene silyl acetals can be used to initiate GTP of methacrylates and acrylates. The new initiators are easy to be prepared using Et3N as catalyst from the reaction of ketones or aldehydes with Me3SiCl. PM-MA and PMA with controlled molecular weight and low polydispersity were obtained by using 1-trimethylsiloxy cyclohexene

2-trimethylsiloxy butene-2

2-methyl 1-trimethylsiloxy pro-pene-1 in the presence of bibenzoate

bifluoride and HgI2. The living nature of polymeriza-tion is shown by the correspondence of theoretical and observed molecular weight and the pre-paration of block copolymer. This initiator system provides a very sueful method for the syn-thesis of A-B-A triblockcopolymer of MMA and BA by using GTP.