| 摘要 |
PURPOSE:Heteropolyacid is used as a catalyst for ring-opening of bicyclic compounds permit bycyclic compound to be used as a material for dental purposes. CONSTITUTION:In the ring-opening of a compound with a bicyclic structure in its molecule such as a compound of the formula (R1, R2 is H, monovalent organic group), a heteropolyacid is used as a catalyst and the reaction is effected at a temperature of 30-130 deg.C for several minutes to several hours. As a heteropolyacid, is preferably cited silicotungstic acid, silicomolybdic acid, phosphotungstic acid, phosphomolybdic acid or their acidic salts and the amount is 0.01-20wt% based on the bicyclic compound. Water is preferably added so that the total amount of water including the crystal water in the polyacid becomes 0.01-20wt% based on the bicyclic compound. |
