In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Nuclear spin-spin relaxation, published in 1962, which mentions a compound: 97739-46-3, Name is 1,3,5,7-Tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane, Molecular C16H21O3P, COA of Formula: C16H21O3P.
The nuclear spin-spin relaxation time, T2, in H at 77.5°K., on a gas sample of approx. 100 Amagats d., was more accurately determined equal to the spin-lattice relaxation time, T1, within ±4%, correcting a previous report (CA 56, 4271h).
Compound(97739-46-3)COA of Formula: C16H21O3P received a lot of attention, and I have introduced some compounds in other articles, similar to this compound(1,3,5,7-Tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane), if you are interested, you can check out my other related articles.
Reference:
Tetrahydropyran – Wikipedia,
Tetrahydropyran – an overview | ScienceDirect Topics