SYNTHESIS OF 4-METHYL-2,3,4-TRICHLOROTETRAHYDROPYRAN AND SEVERAL FEATURES OF THE STEREOCHEMISTRY OF THE NUCLEOPHILIC SUBSTITUTION OF THE α-CHLORINE ATOM

Article abstract of DOI:10.1007/BF00542774

A convenient method has been developed for the synthesis of 4-methyl-2,3,4-trichlorotetrahydropyran by the chlorination of 4-methyl-4-chlorotetrahydropyran, 4-methyl-5,6-dihydro-2H-pyran and its dichloride.A study was carried out on the reactions of 4-methyl-2,3,4-trichlorotetrahydropyran with alcohols, with sodium thiocyanate and Grignard reagents.PMR spectroscopy was used to study the stereochemistry of 4-methyl-2,3,4-trichlorotetrachloropyran and its derivatives, 2-substituted 4-methyl-3,4-dichlorotetrahydropyrans.The dechlorination of these dichloro derivatives by metallic sodium leads to 2,4-disubstituted 5,6-dihydro-2H-pyrans with high regioselectivity