| 摘要 |
3-methyl-3 butene-1-ol acetate and isoprene glycol diacetate are prepared by heating isobutylene, formaldehyde and acetic acid in the absence of catalysts and acetic anhydride at 180-210 DEG C. in the liquid phase the proportions of reactants being 3-10 moles of isobutylene and 3-5 moles of acetic acid per mole of formaldehyde which is conveniently in the form of paraformaldehyde, polyoxymethylene or gaseous formaldehyde. It is preferred to carry out the reaction under pressure in the range 40-150 atm. The reaction mixture is fractionally distilled, after washing out excess acetic acid, to recover the two desired products. Excess isobutylene and acetic acid may be recycled to the reaction zone. Examples are given in which various proportions of reactants are heated in an autoclave yielding the desired acetate and diacetate, which are separated as above. |
