J. E. Roff, R. K. Brown
1973
Citations
0
Influential Citations
3
Citations
Journal
Canadian Journal of Chemistry
Abstract
The reaction of 5-halo-3,4-dihydro-2H-pyran with halogen and sodium methoxide gives in good yield the corresponding 3,3-dihalo-2-methoxytetrahydropyran. The latter, upon treatment with aqueous sodium hydroxide or sodium methoxide in methanol failed to provide 2-methoxytetrahydropyran-3-one but instead gave the 3-halo-2-methoxy-5,6-dihydro-2H-pyran. The ketone, 2-methoxytetrahydropyran-3-one was obtained by the treatment of 5-chloro-3,4-dihydro-2H-pyran with m-chloroperoxybenzoic acid followed by the addition of sodium methoxide.Attempts to prepare the 3,3-dibromo-2-methoxytetrahydropyran by the reaction of 3-bromo-2-methoxytetrahydropyran with bromine were unsuccessful, but gave the ring cleavage product, methyl 2,5-dibromopentanoate.