Vol. 68 b. r. 85-86°, was 87% of the theoretical. Total yield including that containing traces of water was 88.7%.The distillation residues consisted of a mixture of highboiling by-products. Very little unreacted tetrahydrofurfuryl alcohol could be isolated. Small amounts of 5hydroxyvaleraldehyde were present and the remaining components probably were reaction products of dihydropyran with 2-hydroxytetrahydropyran and with tetrahydrofurfuryl alcohol. Since these materials decompose on heating above 100°,3 it was not possible to isolate them in pure form.Various temperature and feed-rate conditions were investigated to establish the limitations and optimum conditions for this procedure. Although the dehydration of tetrahydrofurfuryl alcohol over activated alumina takes place to some extent at temperatures as low as 200°, the best yields and conversion efficiencies are obtained in the range of 350 to 375°at feed rates of 2.0-3.0 g. per minute per 100 cc. of catalyst. Feed rates above 3 g. per minute or temperatures of 400 °or over gave lower yields. For example, yields of 88-90% of the theoretical were consistently obtained at 2.0-2.5 g. per minute at both 350 and 375°whereas 3.1 g. per minute gave 86% yields in both cases.
It is not true that phenols cannot be esterfied by the direct action of an organic acid; includes an experiment demonstrating the fallacy of this common textbook error.
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