Fluoroadamantanes from

N-benzyladamantyl-2-imines, and 2-methyleneadamantanes were studied (352, 353). In particular, X-ray single-crystal analysis confirmed the configuration of the oxathiazoline 185, resulting from the favored attack of nitrile oxide on the 5-fluoroadamantane-2-thione. 2-Silyl-substituted oxathiazole 186 was synthesized by the 1,3-dipolar cycloaddition reaction of phenyl triphenylsilyl thioketone with 4-chlorobenzonitrile oxide (354). 

Fluoroacetamide [640-19-7] M 77.1, m 108°. Crystd from chloroform. 1-Fluoroadamantane see 1-adamantyl fluoride. 

Recently Barton et al. (98) reported extremely selective high-yield reactions at —78°C in CFCl3 between fluorine and adamantane and substituted adamantanes. 1-Fluoroadamantane is produced in 84% yield from adamantane, and 3-fluoro-/V-trifluoroacetyl adamantane is produced from /V-trifluoro-acetyladamantane in 83% yield (98). In addition, Barton, Hesse and coworkers reported regioselective reactions of a number of steroids with yields ranging from 25 to 75% (99). Some of the selectivity in the steroids is rather remarkable and is thought to result from electrophyllic reactions that are strongly influenced by polar substituents on the molecules and by solvents (98,99) p. 73. Although the yields are very impressive in these reports, no information is provided on the conversion or the scale. 

F NMR studies on 5-substituted 2-fluoroadamantanes 64 showed residual contributions which suggest contributions from the resonance structures 65 and 66 to the ground-state structure (equation 23)75. 

Alkanes do not usually react with xenon difluoride at room temperature, while thermally initiated fluorinations of organic molecules have received much less attention than liquid-phase reactions. Zajc and Zupan16 have shown that several hydrocarbons react with xenon difluoride when heated to 95-120 °C. Reproducible results can be observed only when a teflon jacket is used in the stainless reactor with appropriate preconditioning. Cyclohexane is converted to fluorocyclohexane, while the reaction with -hexane gives three monofluoro-substituted products. Fluorination of adamantane results in the formation of four products, from whose distribution it is evident that the difference in the reactivity between the secondary and the tertiary carbon atom is much larger than the difference between the reactivities of the primary and secondary carbon atoms of hexane. Liquid-phase functionalization of a tertiary carbon atom is observed in reactions in carbon disulfide, where 1-fluoroadamantane is formed17. 

Fluoroadamantane (mp 259 260 "C) is obtained under similar conditions in an almost quantitative yield from l-(trimethylsiloxy)adamantane. ... 

Vincent and coworkers oxidized 2-fluoroadamantane in MeCN and obtained a product derived from substitution of the fluorine by an acetamido group. They explained this result by suggesting an elimination of HF from the corresponding cation radical (78),... 

Adamantyl fluoride (1-fluoroadamantane) [768-92-3] M 154.2, m 210-212 (dec), 259-260 (dec). Dissolve in Et20, dry over Na2S04 evaporate to dryness and sublime the residue at 90-100°/12mm. Recryst sublimate from MeOH, m 259-260 . [Zh Org Khim 30 1609 1965.] To remove 1-hydroxyadamantane impurity, dissolve in cyclohexane cool for many hours, filter off the hydroxyadamantane, and evaporate to dryness. Recrystallise the residue from pet ether at -77° and sublime in vacuum, m 210-212° dec (sealed tube). [/ Org Chem 30 789 1965.]... 

Adamantyltetrafluorophosphorane (23) cannot be prepared from the phos-phonyl difluoride (77) by treatment with sulphur tetrafluoride. Instead, it has been prepared in good yield by Lewis-acid-induced cleavage of 1-fluoroadamantane the first time this has been achieved with an alkyl fluoride. ... 

Bridgehead fluoroadamantanes. 1-Bromoadamantane is converted by anhydrous zinc fluoride in refluxing cyclohexane into 1-fluoroadamantane in 61% yield. However, the yield is sensitive to the heat treatment required to obtain anhydrous salt from the tetrahydrate and the reaction becomes increasingly slow as the number of bridgehead bromine atoms is increased. In this case the more expensive silver fluoride is used. Even 1,3,5,7-tetrabromoadamantane can be... 

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