According to Claisen2 dienes can be condensed with phenols in the presence of acid catalysts to give chromans. Thus when isoprene and * Claisen, Ber., 64, 200 (1921).
In connection with the synthesis of tocopherols and the many simpler compounds related to them, large amounts of methylated quiñones were required. The preparation of a kilogram of trimethylquinone by the method used in previous work2 would represent a truly formidable task, even if the necessary starting material, pseudocumidine-5, were available in quantity. Consequently, before undertaking to prepare large amounts of the quinone by this method, we sought to find other, less laborious
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