Borane–amine and tetrahydrofuran–borane adducts reduce 10-undecenoic acid ozonide and derivatives to 1,10-decanediol. Insufficient reagent allows selective reduction at the ozonide function, giving 10-hydroxydecanoic acid and derivatives through aldehyde intermediates. The reagents are not as selective as sodium borohydride. Thermochemical study shows an initial reaction step involving one molecule each of substrate and borane.