Alcohols, Alkoxides, and Ethers

Hydrolysis rate data for the esters MeCOa-CfCFj) and CFj-COj CfCFa) (prepared by treatment of the alcohol with acetic and trifluoroacetic anhydride, respectively, in the presence of 2-methylpyridine) have been compared with those for the esters R COjR (R = Me,R = Et R = Me,R = CFj-CHa R = CF3, R = Et R = CFs R = CFs CHj), differences in the rates being discussed in terms of electronic and steric effects.  

The alkali-metal derivatives of perfluoro-t-butyl alcohol, (CF3)sC OM (M = Li, Na, or K), best prepared by reaction of the alcohol with metal hydride in anhydrous ether, have been shown to resist thermal decomposition [for example, the sodium alkoxide can be melted (143 °Q and distilled (232°C) with no apparent change in composition] the same is true of the alkoxides CF3aC(CF3)3-ONa, Ca,-C(CF8)2-ONa, and (CF3)2CHOM (M = Li or Na), which likewise possess no a-fluorine substituent [cf. 

CFaiCF CfCFaCOa OH to CFa CF C(OH)-CFa CFa with zinc in isopropanol apparently gave only the reduction product CFaiCF-CfCHFaKCFaCO-OH.  

Work on the synthesis of l,l,l-trifluoro-2-trifluoromethylpenta-2,4-diene from hexafluoroacetone has cast considerable doubt on an earlier claim regarding the preparation of this monomer. The successful method now reported involves dehydration of l,l-bis(trifluoromethyl)alken-l-ols obtained from hexafluoroacetone and propene (c/. p. 75), e.g. 

By contrast, hexafluoroacetone olefin adducts of the type RCHj-CHrCH-C(CF3)i,OH and RCH CH-CH3-C(CFg)jOH (R = CHg, n-QH, or n-CjHxx) yield only 5-alkyl-2,2-bistrifluoromethyltetrahydrofurans when heated with sulphuric acid.  

Oxygen.—Alcohols, Alkoxides, and Ethers. The chemistry of fluorinated alkenyl ethers and the conversion of fluoro-olefins into saturated ethers is dealt with in Chapter 2. Information culled from new patent literature 

CH2 C(CFa)2 0 P(0Me)a-0 CH(CFj), by methoxide ion have been sought, and more information pertaining to the chemistry [hydrolysis thermal disproportionation (see p. 247) ] of fluoroalkoxycyclophosphazenes and to the preparation and characterization of poIy[(fluoroalkoxy)phos-phazenes] has become available. 

CX 1(0-S02F)-CC1(0-S02F), respectively. Pyrolysis (250 Q of the cis-trans mixture obtained from the dichiorot clopentene yields the parent 

Interestin y, formation of the stable protonated form of fluoromethanol via treatment of monomeric formaldehyde with HF-SbFs or FSO,H-SbFs-SOjCIF at low temperatures has been observed by n.m.r. techniques  

Isolation of the free alcohol, however, still remains a formidable challenge. 

---