US  6,482,565  Bl  8  7  lb instead of 2-vinyl-1,3-dioxolane of Chemical Formula la,  to obtain the compound represented by Chemical Formula 7  (yield: 55%).  Polyacrolein thus obtained (20 g), ethane-1,2-diol (150 g),  toluene-p-sulfonic acid (1 g) and benzene (200 g) were  placed in a 1000-ml round-bottomed flask, and the reaction  was performed under reflux with a Dean and Stark water  separator attached to the flask, until no more water was  generated. After the reaction was completed, the product  was precipitated from distilled water, to obtain pure com› pound represented by following Chemical Formula 6a  (yield: 45%).  As the reaction catalyst, an acid such as trifluoromethane› sulfonic acid, hydrochloric acid or boron trifluoride-etherate  may be used instead of toluene-p-sulfonic acid. As a reaction  solvent, a non-carbonyl solvent such as tetrahydrofuran may  be used instead of benzene.  The procedure according to Example I was repeated but  using propane-1,2-diol (20 g) instead of ethane-1,2-diol, to  obtain the compound represented by Chemical Formula 7a  (yield: 45%).  In a 250-ml flask, 2-vinyl-1,3-dioxolane (0.3 mole) of  Chemical Formula la, maleic anhydride (0.1 mole),  AIBN  (0.8 g) and tetrahydrofuran ( 41 g) were placed, and the  mixture was reacted at 65° C. under nitrogen or argon  atmosphere for 8 hours. After the polymerization was  completed, the polymers were precipitated from ethyl ether,  and dried in vacuo to obtain pure compound of Chemical  Formula 8 (yield: 80%).  As  a polymerization initiator, conventional radical poly› merization initiators such as lauryl peroxide may be used  instead of  AIBN  (yield: 40% ).  The procedure according to Example 5 was repeated but  using 2-vinyl-1,3-dioxane (0.3 mole) of Chemical Formula  lb instead of 2-vinyl-1,3-dioxolane of Chemical Formula la,  to obtain the compound represented by Chemical Formula 9  (yield: 42%).  In a 100 ml flask, 2-vinyl-1,3-dioxolane (0.1 mole) of  Chemical Formula la, acrylic acid (0.06 mole), tetrahydro› furan (20 g) and AIBN (0.2 g) were placed, and the mixture  was reacted at 65°  C. under nitrogen or argon atmosphere for  8 hours. After the polymerization was completed, the poly- mers were precipitated from distilled water or ethyl ether, to  obtain the compound of Chemical Formula 6 (yield: 60%).  The procedure according to Example 3 was repeated but  using 2-vinyl-1,3-dioxane (0.1 mole) of Chemical Formula  EXAMPLE 4  EXAMPLE 3  0  0  \_J  ~o  \_J  0  0  \_J  <Chemical Formula 9>  <Chemical Formula la>  <Chemical Formula 6>  <Chemical Formula 7a>  <Chemical Formula 7>  <Chemical Formula 6a>  <Chemical Formula lb>  EXAMPLE 5  EXAMPLE 2  ~  0  0  \_J  EXAMPLE 6 