| 摘要 |
A process for preparing acetals of the formula Iwherea) the Rs are, independently of one another, a C1-C20-alkyl or C3-C20-alkenyl radical, orb) the two R radicals together form the members of an unsubstituted or C1-C10-alkyl-substituted 5- to 7-membered cyclic acetal,by reacting 3-methyl-2-butenal in the presence of sulfamic acid, of a N-(C1-C8-alkyl)sulfamic acid or of a N,N-di(C1-C8-alkyl)sulfamic acid as catalyst with:an alcohol of the formula R-OH (IIa), oran orthoester of the formula HC-(OR)3 (III) ora mixture of an alcohol of the formula (IIa) and an orthoester of the formula (III), oran alcohol of the formula HO-(CH2)m-OH (IIb), where m is a number from 2 to 4, and (CH2)m group in the alcohol IIb may be substituted by a C1-C10-alkyl group. |
