Tetrahydro-2-(7-octyn-1-yloxy)-2H-pyran is commonly used as a reagent to synthesize sex pheromones of various insects (e.g. phyllocnistis citrella and autographa gamma L.). Tetrahydro-2-(7-octyn-1-yloxy)-2H-pyran is also used as a reagent to synthesize long chain ω- and (ω-1)-hydroxy fatty acids.