| 摘要 |
Cyclohexene-(1)-dione-(3,6)-tetraalkyldiketals of the formula <IMAGE> (II) wherein each R is a primary or secondary C1-4 alkyl radical are obtained by catalytic hydrogenation of p-benzoquinone tetramethyl-diketal with about 1 mol of H2 per mol of diketal, in a basic medium, at a temperature of from about -10 to +150 DEG C. and optionally by reketalization with a primary or secondary C2-4 alcohol in a slightly acid medium with substantial exclusion of water, at a temperature of from about -10 to +35 DEG C. Cyclohexene-(1)-dione-(3,6)-tetraalkyldiketals, optionally dissolved in an alcohol ROH give hydroquinone dialkyl ethers on acidification and heating to about 60 DEG to 120 DEG C., which ethers are valuable dyestuff intermediates. On catalytic hydrogenation in a basic medium, cyclohexene-(1)-dione-(3,6)-tetraalkyldiketals give the corresponding cyclohexane-(1,4)-tetraalkyldiketals, which are the starting products for the manufacture, for example, of tetracyanoquinodimethane, an important compound in the field of semiconductors. |
