| 摘要 |
<p>The novel hydroquinone derivatives of the formula (I) are useful intermediates for the preparation of coenzyme Q, vitamin K and the polyprenyltrimethylquinones: <IMAGE> (I) wherein R1 is lower alkyl, lower alkoxy lower alkyl or methoxyethoxymethyl, R2 and R3 are each methyl or methoxy, or R2 and R3, taken together with the carbon atoms from which they depend, define a benzene ring, and R4 is a substituted or unsubstituted aromatic hydrocarbon. The compounds (I) are readily prepared either by reacting a Grignard reagent of the formula (II) with a halosulfone (III) in the presence of a copper compound, or by reacting a copper derivative (II') of the Grignard reagent (II) with a halo-sulfone (III), as follows: <IMAGE> <IMAGE> wherein R1, R2, R3 and R4 are defined as above, and X is a halogen atom or a tosyl group.</p> |
