This invention relates to tri- and tetra-substituted-oxetanes, e.g. (.+-.)-cis- and (.+-.)-trans-2-[(4-(4-isopropylpiperazin-1-yl)phenoxy)methyl]-4-(2,4-dihalophenyl)-4-[1H-1,2,4-triazol-1-yl)-methyl]oxetane and tri- and tetra-substituted-tetrahydrofurans, e.g. (.+-.)-cis- and (.+-.)-trans-1-[4-[[2-(2,4-dihalophenyl)tetrahydro-2-[(1H-azol-1-yl)methyl]-5-furanylmethoxy]phenyl]-4-yl-1-substituted piperazine-3-one and related derivatives which exhibit antifungal and antiallergy activities, pharmaceutical composition thereof, methods of their use in treating or preventing susceptible fungal infections and allergic reactions in a host including warm-blooded animals such as humans.