Improved syntheses of certain O-and N-methyl derivatives of 1,3-dihydroxy-acridone are described. Thermal rearrangement of the appropriate 3-α,α-dimethyl-propargyl ethers in the series yields products which may be methylated to acronycine.

The structure, including absolute configuration, of a new compound extracted from Cryptocarya caloneura (Scheff.) Kostermans has been determined by degradation as the (+)-(5S)-δ-lactone of 5-hydroxy-7- phenylhepta-2,6-dienoic acid. The structure has been confirmed by synthesis of its racemate.

α,α-Dimethylpropargyl ethers of simple phenols are readily prepared in high yields. Thermal rearrangement of them affords 2,2- dimethylchromens, also in high yields. These reactions are used to prepare the natural products, ageratochromen, evodionol methyl ether, lapachenole, seselin, luvangetin, and braylin. ��� A base-catalysed Wessely-Moser rearrangement is reported.

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The effect of the solvent and the counter-ion on the ring alkylation of 3- and 4-methoxyphenols by isopentenyl bromide has been examined. Under strictly anhydrous conditions good and consistent yields of the o- isopentenylphenols were obtained with the combination potassium- toluene, but sodium-toluene was more convenient. ��� Boron trifluoride etherate was more satisfactory than stannic chloride, zinc chloride, or phosphoric acid in catalysing the condensation of 3- and 4-methoxy-phenols with 2-methylbut-3-en-2-ol to the corresponding o-isopentenylphenols. Aryl α,α-dimethylpropargyl ethers were partially hydrogenated to the corresponding α,α- dimethylallyl ethers which rearranged in boiling N,N-diethyl-aniline to o-isopentenylphenols in high overall yield.