Formaldehyde → 3-Cyclohexylprop-2-yn-1-ol

To a solution of ethyl magesium bromide (prepared from 2.5 g of magnesium turning and 11.3 g of bromoethane) in ether was added dropwise a solution of 10.2 g of cyclohexylacetylene in ether and the reaction mixture was refluxed for 2 hours. The reaction mixture was cooled to ambient temperature and anhydrous formaldehyde (prepared from the thermal decomposition of 50 g of paraformaldehyde for 20 minutes) was bubbled into the mixture. After cooling, the reaction was quenched with saturated ammonium chloride and extracted with ether (2×100 ml). The combined ether extracts were washed with brine, dried over magnesium sulfate and evaporated to yield the product which was distilled under high vacuum at 68°-74° C. to yield 6.4 g as a colorless liquid.