Surzur, Jean M. published the artcileRadical addition to unsaturated alcohols. IV. Synthesis of 4-cyano-4-carbethoxytetrahydropyrans by intramolecular radical addition, SDS of cas: 30431-99-3, the publication is Bulletin de la Societe Chimique de France (1970), 3070-5, database is CAplus.
Esters (I) (Y = CN) were cyclized with Bz2O2 in refluxing cyclohexane. After decomposition of the excess peroxide, the products were distilled to sep. cyclohexane and the telomers. The distillate was analyzed by vapor-phase chromatog. I (m = 2, n = 0, R = H,Me) gave 71-88% tetrahydropyran derivative (II). I (m = 2; n = 1; R and R1 = H (or Me) gave 96-98% tetrahydropyran derivatives and no 7-membered heterocyclic O-containing compounds could be detected. I (m = n = 1, R = H and Me, and X = CO2Et, Y = CO2Et and CN) gave only polymerized products. This type of reaction gave substituted tetrahydropyran or tetrahydrofuran derivatives which are often not readily accessible by other methods. However, the presence of the O atom makes it necessary to operate at very high dilutions and to use longer reaction times if polymerization, is to be avoided.
Bulletin de la Societe Chimique de France published new progress about 30431-99-3. 30431-99-3 belongs to nitriles-buliding-blocks, auxiliary class Tetrahydropyran,Nitrile,Ester, name is Ethyl 4-cyanotetrahydro-2H-pyran-4-carboxylate, and the molecular formula is C8H7NO4, SDS of cas: 30431-99-3.
Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts