into reaction by heating the mixture to 78 u00b0 to 82 u00b0 c until the amount of formed distilled and recovered water became 51 8 parts after dissolving the reaction product into a mixture of 960 parts of benzene and 240 parts of cyclohexane and neutralizing the thus obtained solution with an aqueous 20 solution of sodium hydroxide the neutralized solution was washed three times with each 500 parts of an aqueous 20 solution of sodium chloride by distilling the solvent off from the washed solution under a reduced pressure 487 parts of a pale yellow viscous liquid was obtained as the final product the product had the following properties ______________________________________number of absorp tion peak position of hereinafter the peak hz referred to hereinafter number ofabsorption referred to absorption position ofpeak number as frequency peak the peak hz ______________________________________no 1 2605 468 no 12 1052 734 2 2595 703 13 960 937 3 2496 093 14 939 453 4 2486 328 15 666 015 5 1974 609 16 644 531 6 1960 937 17 509 765 7 1929 687 18 423 828 8 1919 921 19 380 859 9 1191 406 20 365 234 10 1160 156 21 11 718 11 1126 953 22 1 953______________________________________ of the above shown peaks those of nos 9 10 and 11 are due to the solvent and that of no 22 is due to tetramethylsilane synthesis of one of the ethylenically unsaturated compounds according to the present invention into the same reactor used in example 1 500 parts of the condensate of dipentaerythritol and u03b5 caprolactone 6m prepared in example 3 302 parts of methacrylic acid 25 8 parts of p toluenesulfonic.