3-Methyl-3-buten-1-ol → tetrahydro-2-(3-methyl-3-butenoxy)-4-methyl-2H-pyran

Participants

Reaction Conditions

Reaction Steps

A 300-ml three-necked flask equipped with condensor, stirrer and thermometer was charged with 70 g (0.60 mole) of 2-hydroxy-4-methyltetrahydropgran, 52.46 g (0.61 mole) of 3-methyl-3-buten-1-ol, 150 ml of hexane and 3 g of active clay, and the mixture was stirred at 60° C. for 1 hour. Thereafter, the reaction mixture was analyzed by gas chromatography. The chromatogram showed no peak for 2-hydroxy-4-methyltetrahydropyran but showed a new peak. The active clay was filtered off from the reaction mixture, then, the hexane was distilled off and the residue was distilled under reduced pressure to give 105 g (98% yield) of tetrahydro-2-(3-methyl-3-butenoxy)-4-methyl-2H-pyran as a fraction boiling at 89.5°-90.0° C./10 mm Hg. A nuclear magnetic resonance (NMR) spectrum (in CDCl3) and an infrared absorption spectrum (liquid film-NaCl method) each obtained with the above product are shown in FIG. 1 and FIG. 2, respectively. The NMR spectrum suggested this product was a mixture of 70% of ##STR16## and 30% of ##STR17## Field desorption ionization (FD) mass spectrometry of this product gave M+ =184.

Provenance & Evidence