Hydroquinone → 4-Methyl-3a,4,5,7a-tetrahydro-2-benzofuran-1,3-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Maleic anhydride (68.6 parts) and 70 parts of toluene were introduced into a pressure autoclave, and melted at 55° C. Then, 0.162 part of hydroquinone was added, and 130.9 parts (corresponding to 1.1 moles of trans-1,3-pentadiene per mole of maleic anhydride) of crude trans-1,3-pentadiene composed of 40 % of trans-1,3-pentadiene, 20 % of cis-1,3-pentadiene and 40 % of pentanes was continuously added over 6 hours at 50° C. The temperature was then raised to 60° C., and the reaction was carried out for 3 hours. After the reaction, the reaction mixture was distilled at 90° C. under atmospheric pressure to remove volatile components to give 3-methyltetrahydrophthalic anhydride (melting point 61° C.) in a yield of 99 % as a Diels-Alder reaction product.

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