A study of fluorinated diamond-oid cage molecules : alcohols, esters, and other carbonyl compounds

Aerosol direct fluorination of adamantyl acetate gives 1-F-adamantyl trifluoroacetate and 1-[2-hydryl-F-adamantyl] trifluoroacetate in almost a 1:1 ratio. Aerosol direct fluorination of 1,3-adamantyl bis-acetate gives 1,3-[2-hydr- yl-F-adamantyl] bis-trifluoroacetate. The hydrolysis of 1-F-adamantyl trifluoroacetate and 1-[2-hydryl-F-adamantyl] trifluoroacetate gives correspondent perfluorinated alcohols. 2-[2-Hydryl-adamantyl] alcohol is also synthesized by a reduction of perfluorinated adamantanone. The acidities of F-adamantan-1-ol, 2-hydryl-F-ad- adamantan-1-ol, and 2-hydryl-F-adamantan-2-ol are measured by acid-base titration. The pka values are 5.2, 6.3 and 9.4, respectively. The rates of acetylation reaction of these alcohols correlate with their acidities. The tendency to form hydrogen bonds with hydrogen-bond acceptor solvent depends on the acidity and the steric hindrance of these alcohols.

A series of 1-[2-hydryl-F-adamantyl] esters are synthesized. They are: 1-[2-hydryl-F-adamantyl] methanesulfonate, 1-[2-hydryl-F-adamantyl] trifluoro- acetate, 1-[2-hydryl-F-adamantyl] acetate, 1-[2-hydryl-F-adamantyl] benzoate, 1,3-[2- hydr-yl-F-adamantyl]bis-trifluoroacetate, and 1,3-(2-hydryl-F-adamantyl]bis-benzoate. Two-center and three-center C-H hydrogen bonds are found in these ester system. A linear correlation between the chemical shifts and the ^J;_H-F; coupling constants is observed along with an unusual high field shift of C-H stretching frequencies in these hydrogen-bond systems. A significant deviation from the linear correlation is found in 1-[2-hydryl-F-adamantyl] methanesulfonate.

F-2,6-Adamantanedione is synthesized by aerosol direct fluorination of 2,6-adamantanedione. Photochemical reaction of F,6-adamantanedione gives F-tri- cyclo[3.3.0.0]octane. It is a three-step reaction, the shortest way to approach the bisnoradamantane structure starting with commercially available adamantane.

A series of perfluorinated cage orthoesters are synthesized using aerosol direct fluorination without significant rearrangement products. They are: 4-methyl-2,6,7-tri- oxabicyclo[2.2.2]octane, 1,4-dimethyl-2,6,7-trioxabicyclo[2.2.2]octane, 1-ethyl-4-meth- yl-2,6,7-trioxabicyclo[2.2.2]octane, 2,4,10-trioxaadamantane, and 1-methyl-2,4,10-tri- oxaadamantane.

Hydrolysis of 1-chloro-F-adamantane and 1,3,5-trichloro-F-adamantane in the presence of KOH and catalyst, 18-crown-6, give 1-hydryl-F-adamantane and 1,3,5-tri- hydryl-F-adamantane, respectively. The normal strong oxidizing reagents do not oxidize 1-hydryl-F-adamantane. 5-Hydryl-F-adamantan-2-one is synthesized by reducing 5-chloro-F-adamantan-2-one to E, 2-2,5-dihydryl-F-adamantan-2-ol, and oxidizing the alcohols.