It was found that ethyl 4,4-dimethoxy-2-(phenylthio)butyrate and 3-tosylpropanal ethylene acetal are useful starting materials for the preparation of 3-substituted furans. Several 3-substituted furans, including dendrolasin [3-(4,8-dimethyl-3,7-nonadienyl)-furan], were prepared by the reaction of these compounds with alkyl halides in good yields.

It was found that ethyl 4,4-dimethoxy-2-phenylthiobutyrate is an useful reagent for the preparation of 3-substituted furans from alkyl halides. 3-Benzylfuran, 3-geranylfuran (nordendrolasin), and 3-octadecylfuran were prepared by the method in good yields.

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A hydrogen gas thermometer for the standard of the low temperature measurement was constructed wholly of glass. The accuracy of temperature obtained, ±0.036° at 0°C. and ±0.025° at −200°C., was discussed, the volume of thermometer bulb, the dead spaces, and the temperature of the room being taken into consideration. The determination of the boiling points of liquid nitrogen and liquid oxygen and that of the sublimation point of solid carbon dioxide were made with this thermometer. The calibration of copper-constantan thermocouples was also made against the thermometer at various low temperatures.