Cyclic ethers phosgene

The reactions of phosgene with cyclic ethers provides a convenient means, in some cases, of preparing chloroalkyl chloroformates. The reactions are usually fast and, unlike those of the alcohols, do not co-produce hydrogen chloride. 

Cyclic ethers would be expected to undergo ring-opening reactions with carbonyl difluoride as with phosgene. Epoxyethane reacts with two moles of COFj, in the presence of pyridine, according to the following equations [24a] ... 

Phosgene is reported to combine with a wide range of oxygenated materials, including alcohols, ethers, ketones, carboxylic acids, anhydrides, lactones, esters, carbonic acid derivatives, etc. Only the reactions of COCIF with alcohols, phenols and cyclic ethers have been reported, resulting usually in the generation of fluoroformates. Such materials can often be usefully converted into the corresponding fluoro compound by means of decarboxylation in the presence of BF3, EtjO, pyridine, or other materials. 

Cyclic silyl ethers undergo ring opening with phosgene to produce chloroformates... 

Dithiocarboxylic acid esters. 1.5-2 moles of phosgene passed at 25-30° into a soln. of propionic acid piperidide in toluene, and the product isolated after 4-5 hrs. propionic acid piperidide chloride (Y 90-95%) suspended in abs. ether, treated at 0° with ethyl mercaptan, the ether removed, the residue treated with dimethylformamide and pyridine, HgS introduced 4 hrs. at 0°, and allowed to stand several hrs. at room temp. ethyl dithiopropionate (Y 86%). F. e., also thionocarboxylic acid esters by initial treatment with alcohol, isolation of thiolic acid esters, and f. reactions, also ring closures to hetero-cyclics, s. H. Eilingsfeld, M. Seefelder, and H. Weidinger, B. 96, 2671 (1963). 

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