Silver fluoride, reaction with alcohols

O-isopropylidene derivative (57) must exist in pyridine solution in a conformation which favors anhydro-ring formation rather than elimination. Considerable degradation occurred when the 5-iodo derivative (63) was treated with silver fluoride in pyridine (36). The products, which were isolated in small yield, were identified as thymine and l-[2-(5-methylfuryl)]-thymine (65). This same compound (65) was formed in high yield when the 5 -mesylate 64 was treated with potassium tert-hx Xy -ate in dimethyl sulfoxide (16). The formation of 65 from 63 or 64 clearly involves the rearrangement of an intermediate 2, 4 -diene. In a different approach to the problem of introducing terminal unsaturation into pento-furanoid nucleosides, Robins and co-workers (32,37) have employed mild base catalyzed E2 elimination reactions. Thus, treatment of the 5 -tosylate (59) with potassium tert-butylate in tert-butyl alcohol afforded a high yield of the 4 -ene (60) (37). This reaction may proceed via the 2,5 ... 

Selective reaction of the bromochloro compound 83 with silver fluoride in acetonitrile gave a good yield of the product of nucleophilic displacement of bromide with inversion of configuration, namely, 151, and treatment with an excess of the reagent afforded25 the g m-difluoride (152). With alcohols in the presence of silver triflate, compound 83 affords access to orthoesters (for example, the dimethyl compound 153), and with diols sp/ro-analogs (for example, 154, which has the orthoester structural feature of the orthosomy-cins), are obtained.88... 

Cesium fluoride reacts with epoxides to form cesium alcoholates that can be transformed into a plethora of ethers and esters in good yield, for example, reaction of 12 to give 13. Methyl-ation with iodomethane is common. For sensitive alcohols silver oxide is the base of choice." No elimination to the a,)S-unsaturated sulfoxides was reported, when alcohols 14 were treated w ith iodomethane in dimethylformamide to give ethers 15." ... 

ACETYLENOGEN (75-20-7) Contact with water, moist air, steam, alcohols forms explosive acetylene gas, corrosive calcium hydroxide, and heat. Violent reaction with acid, acid fumes, copper salts, strong oxidizers (bromine, chlorine, iodine, etc.), iron trichloride, tin dichloride, silver nitrate. Incompatible with oxidizers, hydrogen chloride, methanol, copper salt solutions, lead fluoride, magnesium, selenium, sodium peroxide, stannous chloride, sulfur. 

GLYCYL ALCOHOL (56-81-5) Combustible liquid (flash point 390°F/199°C). Violent reaction with strong oxidizers, acetic anhydride, calcium hypochloride, chlorine, chromic anhydride, chromium oxide, ethylene oxide, hydrogen peroxide, phosphorus triiodide, potassium permanganate, potassium peroxide, silver perchlorate, sodium hydride, sodium peroxide, sodium triiodide, sodium tetrahydroborate. Incompatible with strong acids, caustics, aliphatic amines, isocyanates, uranium fluoride. Able to polymerize above 293°F/145°C. 

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