V. G. Ratner

Synthesis of bis(polyfluoroalkyl)-1,3,5-triketones

A preparative procedure was developed for the synthesis of polyfluoroalkyl-1,3,5-triketones by condensation of acetone or fluorinated methyl β-diketones with methyl perfluorocarboxylates in the presence of LiH. In the case of CF3 substituents, the formation of triketone was accompanied by the formation of its cyclic hydrate, viz., of dihydroxytetrahydropyranone.

Synthesis of polyfluoroalkyl-containing 1,3,5-triketones

Abstract Synthesis of polyfluoro 1,3,5-triketones by modification of Claisen condensation is described.

Trifluoromethylated 1,2λ5σ4-oxaphospholanes via λ5σ5P tricyclic phosphoranes from 4,4,4-trifluoro-3-hydroxy-1-phenylbutane-1-one and dichlorophosphines. Molecular structure of a trapped phosphonite

Abstract Reacting 4,4,4-trifluoro-3-hydroxy-1-phenylbutane-1-one (1) with the dichlorophosphines RPCl 2 ( 2a , R = Me; 2b , R = Ph) gave the phosphonites 3a and 3b , which, in the case of 3a , was trapped using hexaHuoroacetone to furnish the 1,3,2λ 5 σ 5 -dioxaphospholane 4a . In a concerted mechanism, compounds 3a and 3b rearranged forming the thermally unstable tricyclic diastereoisomeric phosphoranes 5a and 5b . After splitting off 1,1,1-trifluoro-4-phenyl-2-butene-4-one (6) the diastereoisomeric 1,2λ 5 σ 4 -oxaphospholanes 7a and 7b were obtained. The molecular structure of 4a (triclinic, P , a =1020.3(1) pm, b =1239.0(1) pm, c =1298.7(2) pm, a = 85.55(1) °, 0 = 70.10(1) °, γ=79.85(1) °) was determined.

Synthesis of fluoroalkyl-containing β-hydroxyketones by reduction of the corresponding β-diketone derivatives

The rcgioselective synthesis of fluoroalkyl-containing P-hydroxyketones by the reduction of the salts of the corresponding β-diketones with LiAlH4 was proposed. This is the sole method for the synthesis of β-hydroxyketones with two fluoroalkyl substituents.

Reactions of fluoroalkyl-containing bis-β-diketones with hydrazine and hydroxylamine

Polyfluoroalkyl-containing bispyrazoles, bis(5-hydroxy-Δ2-isoxazolines), and bisisoxazoles were synthesized for the first time by reactions of polyfluoroalkyl-containing bis-β-diketones with hydrazine, phenylhydrazine, and hydroxylamine, respectively.

Polyfunctional fluoroalkyl-containing carbonyl compounds in the synthesis of heterocycles

Efficient procedures for the regioselective synthesis of fluoroalkyl-containing threefive-, six-, and seven-membered heterocycles as well as of related fused compounds, namely, α,β-epoxyketones, α,β-aziridinylketones, pyrazoles, pyrazolines, isoxazolines, 1,2-dithiolenes, amino- and mercaptopyrimidines, Δ3,5-2-thioxo-1,3,2-thiazaphosphorines, Δ3,5-2-thioxo-1,3,2-oxazaphosphorines, 2,3-dihydro-1,4-diazepines, azirino[1,2-a]quinoxalines, benzo[b]-and naphtho[2,3-b]-1,4-diazepines, and triazolopyridazines, which have been developed by the authors and coworkers, are summarized. The α- and β-functionalized fluoroalkylcontaining carbonyl compounds (β-diketones, β-ketoesters, their salts, regioisomeric β-aminovinyl ketones, β-aminovinylthiones, β-hydroxyketones, α,β-enones, and their halogen derivatives) were used as synthons in the processes of formation of the above-mentioned heterocycles.

Unexpected reaction of 1,1,1,10,10,10-hexafluorodecane-2,4,7,9-tetrone with methyl trifluoroacetate

Hexane-2,5-dione or 1,1,1,10,10,10-hexafluorodecane-2,4,7,9-tetrone react with methyl trifluoroacetate in the presence of LiH to give, upon treatment with diluted acid, 6-hydroxy-9-oxo-2,4,10-tris(trifluoromethyl)-3,11,12-trioxatetracyclo[5,2,1,02,6,04,10]dodecane. The structure of this compound was determined by X-ray diffraction study.

Ring opening of fluoroalkyl-containing α,β-epoxyketones by aromatic amines

Aromatic amines cause α,β-epoxyketones containing a β-fluoroalkyl group to undergo ring opening at the α-position to give α-amino-β-hydroxyketones.

Oxidation of fluoroalkyl-substituted allylic alcohols: a synthesis of fluorinated α,β-epoxyketones

Fluoroalkyl-substituted allylic alcohols are readily and selectively oxidized at the hydroxyl group with the Swern or Dess-Martin reagents to give α,β-unsaturated ketones, and on treatment withm-chloroperbenzoic acid ortert-butyl hydroperoxide they are oxidized to the corresponding epoxyalcohols. The latter are oxidized by Swern or Dess-Martin reagents at the hydroxyl group to α,β-epoxyketones, which form hydrates stable under the conditions of isolation.

α-Tosyloxylation of fluorosubstituted β-diketones

The interaction of fluorinated β-diketones with [hydroxy(tosyloxy)iodo]benzene leads to α-tosyloxy-β-diketones existing in the form of stable hydrates.