| 摘要 |
<p>Preparation of 2,3,5-trimethylhydroquinone diester derivatives (I) comprises treatment of 2,6,6-trimethyl-cyclohex-2-en-1,4-dione (ketoisophorone) (II) with an acylating agent in the presence of a catalytic amount of a protic acid (i.e. an ortho-boric acid, a boric acid anhydride, a boric acid triester, a hydroxycarboxylic acid or a di- or tri-carboxylic acid optionally containing hydroxy groups). Preparation of trimethylhydroquinone diester derivatives of formula (I) comprises treatment of 2,6,6-trimethyl-cyclohex-2-en-1,4-dione (ketoisophorone) of formula (II) with an acylating agent in the presence of a catalytic amount of a protic acid (i.e. an ortho-boric acid, a boric acid anhydride, a boric acid triester, a hydroxycarboxylic acid or a di- or tri-carboxylic acid optionally containing hydroxy groups. N.B. R and R1 are not defined in the main claim, but in a dependent claim are defined as: R, R1 = optionally substituted 1-20 (especially 2-4)C aliphatic, alicyclic residue or aryl (especially phenyl).</p> |
