OXIDATIVE FORMYLATION AND CHLOROMETHYLATION AS ALTERNATIVE PATHWAYS TO CHLOROFORMYLATION IN THE REACTION OF O- AND S-HETEROCYCLIC KETONES WITH DIMETHYLFORMAMIDE-PHOPHORUSOXYCHLORIDE

Article abstract of DOI:10.1016/S0040-4039(00)97850-X

The action of DMF-POCl3 at 20 deg C on tetrahydro-4H-pyran-4-one, tetrahydro-4H-thiopyran-4-one, chroman-4-one, and thiochroman-4-one affords the corresponding β-chlorovinylaldehydes, whereas with excess DMF-POCl3 at 100 deg C chroman-4-one affords 3-(chloromethyl)chromone, and thiochromanone gives 3-formylthiochromone.