Thermische Lactonisierung von Estern γ-Brom-α, β-ungesättigter Carbonsäuren zu Δα-Butenoliden. Direkte γ-Bromierung von α, β-ungesättigten Säuren

By heating with iron powder at 120–150° some γ-bromo-α, β-unsaturated carboxylic methyl esters, and, less smothly, the corresponding acids, were lactonized to Δ^7alpha;-butenolides with elimination of methyl bromide. The following conversions have thus been made: methyl γ-bromocrotonate ( 1c ) and the corresponding acid ( 1d ) to Δ^α-butenolide ( 8a ), methyl γ-bromotiglate ( 3c ) and the corresponding acid ( 3d ) to α-methyl-Δ^α-butenolide ( 8b ), a mixture of methyl trans- and cis-γ-bromosenecioate ( 7c and 7e ) and a mixture of the corresponding acids ( 7d and 7f ) to β-methyl-Δ^α-butenolide ( 8c ). The procedure did not work with methyl trans-γ-bromo-Δ^α-pentenoate ( 5c ) nor with its acid ( 5d ). Most of the γ-bromo-α, β-unsaturated carboxylic esters ( 1c, 7c, 7e and 5c ) are available by direct N-bromosuccinimide bromination of the α, β-unsaturated esters 1a, 7a and 5a ; methyl γ-bromotiglate ( 3c ) is obtained from both methyl tiglate ( 3a ) and methyl angelate ( 4a ), but has to be separated from a structural isomer. The γ-bromo-α, β-unsaturated esters are shown by NMR. to have the indicated configurations which are independent of the configuration of the α, β-unsaturated esters used; the bromination always leads to the more stable configuration, usually the one with the bromine-carrying carbon anti to the carboxylic ester group; an exception is methyl γ-bromo-senecioate, for which the two isomers (cis, 7e , and trans, 7d ) have about the same stability. The N-bromosuccinimide bromination of the α,β-unsaturated carboxylic acids 1b , 3b , 4b , 5b and 7b is shown to give results entirely analogous to those with the corresponding esters. In this way γ-bromocrotonic acid ( 1 d ), γ-bromotiglic acid ( 3 d ), trans- and cis-γ-bromosenecioic acid ( 7d and 7f ) as well as trans-γ-bromo-Δ^α-pentenoic acid ( 5d ) have been prepared. Iron powder seems to catalyze the lactonization by facilitating both the elimination of methyl bromide (or, less smoothly, hydrogen bromide) and the rotation about the double bond. α-Methyl-Δ^α-butenolide ( 8b ) was converted to 1-benzyl-( 9a ), 1-cyclohexyl-( 9b ), and 1-(4′-picoly1)-3-methyl-Δ^α-pyrrolin-2-one ( 9 c ) by heating at 180° with benzylamine, cyclohexylamine, and 4-picolylamine. The butenolide 8b showed cytostatic and even cytocidal activity; in preliminary tests, no carcinogenicity was observed. Both 8b and 9c exhibited little toxicity.     

Isomerization polymerization of 2-vinyl-1,3-dioxolane by α,α′-azobisisobutyronitrile or by γ-ray irradiation

2-Vinyl-1,3-dioxolane was polymerized by use of α,α′-azobisisobutyronitrile (AIBN) or by γ-ray irradiation. The polymer obtained was white amorphous powder which melted at ca. 70°C. and was soluble in chloroform, acetone, and p-dioxane. The infrared spectrum of the polymer indicated peaks at 1735 cm.^?1 characteristic of the carbonyl group, and at 1200–1000 cm.^?1 characteristic of the acetal group, while no absorption at 990 and 3100 cm.^?1 due to the vinyl group was observed. The spectra of the polymers obtained by AIBN and by γ-ray irradiation were essentially identical. The saponified product of the polymer was white powder and its reduced viscosity was a little larger than that of the original polymer. These results indicate that the polymer has no ester unit in the main chain. The results of gas chromatographic analysis of the saponified product of the polymer, indicate the presence of a small amount of ethyl alcohol. The results of the saponification showed that the ester content in the polymer varied from 7 to 25% depending upon the polymerization temperature. These results indicate that 2-vinyl-1,3-dioxolane polymerized by AIBN or by γ-irradiation with two modes of vinyl and hydrogen migration, yielding a copolymer having the unit structures      

Synthesis and Antimicrobial Activity of Some Novel [4‐(1,2,3‐thiadiazol‐4‐yl)phenoxy]methylene anchored 1,3,4‐triazoles and 1,3,4‐thiadiazoles

A series of novel [4‐(1,2,3‐thiadiazol‐4‐yl)phenoxy]methylene anchored 1,3,4‐triazoles ( 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h ) and 1,3,4‐thiadiazoles ( 9a , 9b , 9c , 9d , 9e , 9f , 9g , 9h , 9i ) were synthesized from thiosemicarbazide ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j ). The structures of these newly synthesized compounds were confirmed on the basis of IR, ¹H‐NMR, mass spectral techniques, and elemental analysis. The in vitro antimicrobial screenings of the synthesized compounds were carried out against four bacterial pathogens, namely Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and three fungal pathogens Candida albicans, Aspergillus niger and Aspergillus clavatus, using broth microdilution minimum inhibitory concentration method. The compounds 7d , 7j , 8a , 9a , 9b , and 9i exhibited promising antibacterial activity against the tested strains, whereas some compounds were found to be active against one of the tested bacterial strains.     

Study on the synthesis of the lanthanide chelates of α′-(trifluoromethyl)polyfluoroalkyl β-diketones and their application as 1H NMR shift reagents

The synthesis of the lanthanide chelates of α′-(trifluoromethyl)polyfluoroalkyl β-diketones Ln {CF₃CF₂[CF₂OCF(CF₃)]_n COCHCOC(CH₃)₃}₃ [ 1 , n=1; Ln=Eu (1a) , Pr (1b) , Nd (1c) , Sm (1d) , Gd (1e) , Tb (1f) , Dy (1g) , Er (1h). 2 , n=2; Ln=Eu (2a) , Pr (2b) , Nd (2c) , Sm (2d) , Gd (2e) , Tb (2f) , Dy (2g) and Er (2h) ] was reported and the ¹H NMR shift properties were studied using alcohol, ketone, ether and amine as substrates. Compounds 1a, 1b, 2a and 2b induce shifts similar to that induced by Ln(fod)₃ (Ln=Eu, Pr). However compounds 1a and 2a are superior to Eu(fod)₃, because their ¹H signal shifts to higher field in the presence of substrate than that of Eu(fod)₃, does. For example, Δh for 1a and 2a is close to zero ppm in the presence of alcohol. A very satisfactory first order spectra can be obtained using 1a, 2a, 1b and 2b as ¹H NMR shift reagents. 1c, 1f, 1g, 2c, 2f and 2g produce upfield shifts, and 1h and 2h produce downfield shifts. 1c and 2c induce shifts smaller than that of 1b and 2b , whereas 1f, 1g, 1h, 2f, 2g and 2h induce very large shifts.     

Full Characterization and some reactions of 1‐(2‐adamantyl)‐3‐(1‐adamantyl)aziridin‐2‐one

We found that 1‐(2‐adamantyl)‐3‐tert‐butylaziridin‐2‐one ( 5a ) is unstable. It slowly decomposes at room temperature, although detectable by IR spectroscopy (1840 cm^?1 band in CCl₄). On the other hand, a closely related analogue, 1‐(2‐adamantyl)‐3‐(1‐adamantyl)aziridin‐2‐one ( 5b ), is very stable, in concurrence with an earlier report [1]. We fully characterized aziridinone 5b , identified its thermal decomposition products ( 7 and 8 ) and reacted it with two aprotic ionic (tBuO^? and HO^?) and one protic non‐ionic nucleophile (benzylamine). All three products ( 9b , 10 , and 11 ) result from exclusive cleavage of the lactam (1‐2) bond.     

Structural Characterization and Enzymatic Degradation of α‐, β‐, and γ‐Crystalline Forms for Poly(β‐propiolactone)

A structural comparison of three different crystalline forms of poly(β‐propiolactone) (PPL) was carried out by wide‐angle X‐ray diffraction, Fourier‐transform infrared spectroscopy, and differential scanning calorimetry. The α‐form in a hot‐drawn and annealed film represents a 2₁ helix conformation. The β‐form in a cold‐drawn and annealed film represents a planar zigzag conformation. The γ‐form in an oriented sedimented mat of solution‐grown chain‐folded lamellar crystals also implies a planar zigzag conformation. The solution‐cast film depicts similar outlines with the γ‐form in lamellar crystals in all the experimental measurements, suggesting that the molecular chain in the solution‐cast film has a planar zigzag conformation. While elongation at break decreased, tensile strength and Young's modulus increased with an increase in the crystallinity, independent of the crystalline forms. The influence of the enzymatic degradation of these crystal structures has been investigated by using an extracellular PHB depolymerase purified from Ralstonia pickettii T1. The rate of degradation was in the order of β‐form > α‐form > solution‐cast (γ‐form) film, and the different surface morphologies after partial enzymatic degradation were observed in scanning electron micrographs. It is suggested that the crystal structure is one of the important factors for determining the rate of degradation together with crystallinity.

Enzymatic degradation profiles of poly(β‐propiolactone) films.     

The formation of 3‐ferrocenylpyrazole‐4‐carboxylates and alkylhydrazine insertion products from α‐ferrocenylmethylidene‐β‐oxocarboxylates

The reactions of α‐ferrocenylmethylidene‐β‐oxocarboxylates ( 1 , 2 , 3a , and 3b ) with N‐methyl‐ and N‐(2‐hydroxyethyl)hydrazines ( 5a , 5b ) afford ethyl 1‐alkyl‐5‐aryl(methyl)‐3‐ferrocenylpyrazole‐4‐carboxylates ( 6a , 6b , 6c , 6d , 6e ) (～50%) and N‐alkylhydrazine insertion products, viz., ethyl (N′‐acyl‐N′‐alkylhydrazino)‐3‐ferrocenylpropanoates ( 7a , 7b , 7c , 7d , 7e ) (～20%) and 1‐acyl‐2‐(N′‐alkyl‐N′‐ethoxycarbonylhydrazino)‐2‐ferrocenylethanes ( 8a , 8b , 8c , 8d , 8e ) (～10%). The structures of the compounds obtained were established based on the spectroscopic data and X‐ray diffraction analysis (for pyrazoles 6a and 6b ). J. Heterocyclic Chem., (2011).     

The Course of the Catalytic Hydrogenation/Isomerization Reaction of Steroidal Ring B Olefins in the 13β- and 13α-Series

The course of the catalytic hydrogenation and isomerization (H₂/Raney-Ni/dioxane or H₂/Pd/C/EtOH) of Δ^5.7-, Δ⁷-, Δ⁸-, and Δ⁸⁽¹⁴⁾-steroid olefins was shown to depend strongly on the configuration at C(13). The known hydrogenation/isomerization of reactions of Δ^5.7-dienes in the 13β-series to Δ⁷-(H₂/Raney-Ni/dioxane) and Δ⁸⁽¹⁴⁾-olefins (H₂/Pd/C/EtOH) were also confirmed in the 3β, 19-epoxy-13β- and 3-Oxo-19-acetoxy-13β-steroid series (e.g. 32 → 35 → 37 , Scheme 3). On the other hand, in the corresponding 13α-steroid series the same reactions afforded the Δ⁷-. and the Δ⁸-olefins (mixture of products with H₂/Raney-Ni/dioxane; quantitatively the Δ⁸-compounds with H₂/Pd/C/EtOH; s. e.g. Scheme 3). A similar dependence on the C(13) configuration was observed in the allylic oxidation of these olefins with SeO₂ (Fieser's test, see Table), and in the acid catalyzed opening of the 7α, 8α-epoxides (e.g. 60 → 62 + 63 in the 13β-series, and 56 → 64 + 65 in the 13α-series, Scheme 8).     

Nucleophilic Substitution in the Allylic System of Codeine and Pseudocodeine: Reactions with lithium cyano(methyl)-and (aryl)cyanocuprates. Crystal and molecular structure of 8α-phenyl-6,7-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan and 6α-phenyl-7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan

Nucleophilic substitution of 6β-chloro-7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan ( 1 ) and 8α-bromo-6,7-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan ( 2 ) with lithium cyano(methyl)- and (aryl)cyanocuprates(I) ( 5a–c ) was accompanied by allylic rearrangement with both change and retention of orientation of the substituting group (Scheme 1, Table 1). Nucleophilic substitution in 7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6α-yl methanesulfonate ( 3 ) and 7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6β-yl methanesulfonate ( 4 ) proceeded without allylic rearrangement with both change and retention of the orientation of the substituting group (Scheme 2, Table 1). X-Ray diffraction studies of the products 6,7-didehydro-4,5α-epoxy-3-methoxy-17-methyl-8α-phenylmorphinan ( 6b ) and 7,8-didehydro-4,5α-epoxy-3-methoxy-17-methyl-6β-phenylmorphinan ( 7b ) were carried out (Figs. 1 and 2).     

Konformationsanalysen von Modell-Tripeptiden: Der Einfluss von α,α-disubstituierten α-Aminosäuren auf die Sekundärstruktur. Teil II. Röntgenstrukturanalyse und Konformationsenergie-Berechnungen

Conformational Analysis of Tripeptide Models: The Influence of α,α-disubstituted α-Amino Acids on the Secondary Structure. X-Ray Analysis and Conformational Energy Calculations The X-ray analysis of tripeptide Z-Ile-Val(2-Me)-benzocaine ( 1f ) reveals the presence of a type-III β-turn. Moreover, MMP2 calculations on tripeptides, e.g. Z-Ile-Aib-benzocaine ( 1c ), Z-Ile-D -Val(2-Me)-benzocaine ( 1g ), Z-Ile-Gly(2,2-Pr₂)-benzocaine ( 1h ), Z-Ile-Gly-benzocaine ( 1a ), and 1f , fit well into the frame of NMR and CD investigations. They allow considerations on the relative stability of different types of β-turns depending on the peptide sequence, e.g. the kind of α,α-disubstituted amino-acid moieties.     

Reactions of α,β‐Unsaturated Thioamides with Diazo Compounds

Several reactions of the α,β‐unsaturated thioamide 8 with diazo compounds 1a – 1d were investigated. The reactions with CH₂N₂ ( 1a ), diazocyclohexane ( 1b ), and phenyldiazomethane ( 1c ) proceeded via a 1,3‐dipolar cycloaddition of the diazo dipole at the C?C bond to give the corresponding 4,5‐dihydro‐1H‐pyrazole‐3‐carbothioamides 12a – 12c , i.e., the regioisomer which arose from the bond formation between the N‐terminus of the diazo compound and the C(α)‐atom of 8 . In the reaction of 1a with 8 , the initially formed cycloadduct, the 4,5‐dihydro‐3H‐pyrazole‐3‐carbothioamide 11a , was obtained after a short reaction time. In the case of 1c , two tautomers 12c and 12c ′ were formed, which, by derivatization with 2‐chlorobenzoyl chloride 14 , led to the crystalline products 15 and 15 ′. Their structures were established by X‐ray crystallography. From the reaction of 8 and ethyl diazoacetate ( 1d ), the opposite regioisomer 13 was formed. The monosubstituted thioamide 16 reacted with 1a to give the unstable 4,5‐dihydro‐1H‐pyrazole‐3‐carbothioamide 17 .     

2,4-Disubstituted Pyrrolo[2,3-d]pyrimidine α-D- and β-D-Ribofuranosides Related to 7-Deazaguanosine

Nucleobase-anion glycosylation (KOH, tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1), MeCN) of the pyrrolo[2,3-d]pyrimidines 4a – d with 5-O-[(1,1-dimethylethyl)dimethylsilyl]-2,3-O-(1-methylethylidene)-α-D -ribo-furanosyl chloride ( 5 ) gave the protected β-D -nucleosides 6a – d stereoselectively (Scheme 1). Contrary, the β-D -halogenose 8 yielded the corresponding α-D -nucleosides ( 9a and 9b ) apart from minor amounts of the β-D -anomers. The deprotected nucleosides 10a and 11a were converted into 4-substituted 2-aminopyrrolo[2,3-d]-pyrimidine β-D -ribofuranosides 1 . 10c , 12 , 14 , and 16 and into their α-D -anomers, respectively (Scheme 2). From the reaction of 4b with 5 , the glycosylation product 7 was isolated, containing two nucleobase moieties.     

Stereoselective Synthesis of Indazole 2′-Deoxy-β-D-ribonucleosides: Glycosylation of the Nucleobase Anion

The glycosylation of indazolyl anions derived from 4a , b with 2-deoxy-3,5-bis-O-(4-methylbenzoyl)-α-D -erythro-pentofuranosyl chloride ( 5 ) is described. The reaction was Stereoselective – exclusive β-D -anomer formation – but regioisomeric N¹- and N²-(2′-deoxy-β-D -ribofuranosides) (i.e. 6a and 7a , resp., and 6b and 7b , resp.) were formed in about equal amounts. They were deprotected to yield 8a , b and 9a , b . Compound 1 , related to 2′-deoxyadenosine ( 3 ), and its regioisomer 2 were obtained from 8b and 9b , respectively, by catalytic hydrogenation. The anomeric configuration as well as the position of glycosylation were determined by 1D NOE-difference spectroscopy. The first protonation site of 1 and 2 was found to be the NH₂ group. The N-glycosylic bond of 1H-indazole N¹-(2′-deoxyribofuranosides) is more stable than that of the parent purine nucleosides. Compound 1 is no substrate for adenosine deaminase.     

Radical-initiated homopolymerization and copolymerization of ethyl α-hydroxymethylacrylate

Ethyl α-hydroxymethylacrylate (EHMA) was synthesized and homopolymerized in bulk and in solution. The poly(EHMA) is readily soluble in alcohol, acetone, tetrahydrofuran, and methylene chloride at room temperature. Intramolecular lactone formation occurred when poly(EHMA) was heated to 180–230°C. The kinetics of EHMA homopolymerization was investigated in ethyl acetate, using α,α′-azobisisobutylonitrile as an initiator. The rate of polymerization R_p was expressed by R_p = k[AIBN]^0.50[EHMA]^1.4 and the overall activation energy was calculated as 71.9 kJ/mol. Kinetic constants for EHMA polymerization were obtained as follows: k_p/k = 0.17L^0.9mol^?0.9s^?0.5; 2fk_d = 1.5 × 10^?5 s^?1. The relative reactivity ratios of EHMA(M₂) copolymerization with styrene (r₁ = 0.472, r₂ = 0.564) in ethyl acetate were obtained. Applying the Q-e scheme led to Q = 0.84 and e = 0.35 for EHMA.     

The Crystal and Molecular Structure of 3-Oxo-17β-acetoxy-Δ4-14α-methyl-8α, 9β, 10α, 13α-estrene

The crystal and molecular structure of 3-oxo-17β-acetoxy-Δ⁴-14α-methyl-8α, 9β, 10α, 13α-estrene, C₂₁H₃₀O₃, has been determined by X-ray diffraction analysis. The crystals belong to the orthorhombic space group P2₁2₁2₁, with the cell dimensions a = 12.093 Å, b = 19.667 Å, c = 7.746 Å; Z = 4. Intensity data were collected at room temperature with an automatic four-circle diffractometer. The structure was solved by direct methods and the parameters were refined by least-squares analysis. All the hydrogen atoms were included in the refinement. The final R value was 0.038 for 1413 observed reflections. The conformation of ring A is intermediate between a half-chair and a 1, 2-diplanar form. The hydrogens at C(9) and C(10) are anti, the B/C ring junction is trans, and rings B and C adopt chair conformations. Ring D is cis fused and is halfway between C₂ and C_s forms.     

Synthese von β-D-Glucopyranosiden einiger hydroxylierter Vitamin-D-Verbindungen

Synthesis of β-D -Glucopyranosides of some Hydroxylated Vitamin-D Compounds Cholesta-5, 7-diene-1α, 3β-diol (1a) was glycosylated with ‘α-acetobromoglucose’ (2) as well as with ‘α-acetobromocellobiose’ (4) to yield the 3-(glycosides) 1b and 1c , respectively. Irradiation of these products with UV light followed by thermal isomerization led to the corresponding vitamin-D derivatives 3a and 3c. Direct glucosylation of vitamin D₃ (3f) and vitamin D₂ (5a) with 2 gave the derivatives 3g and 5b , respectively. With 25-hydroxycholecalciferol ( = calcidiol; 6a ) as substrate, besides the 3-(glucoside) 6b small amounts of the C(25)-analog 6c were formed. The reaction of 1α, 25-dihydroxycholecalciferol ( = calcitriol; 6e ) with 2 furnished the 3- and the 1-(glucoside) ( 6f and 6g , respectively) as the major components and the C(25)-analog 6h in minor quantity. From the acetylated 3-(glucosides) 3a, 3g, 5b, 6b , and 6f , the free glucopyranosides 3b, 3h, 5c, 6d , and 6i , respectively, were prepared as well as the free glucopy-ranosyl-glucopyranoside 3d from the acetylated disaccharide 3c.     

Anionic copolymerizations of acrylonitrile with β-propiolactone

Anionic copolymerizations of acrylonitrile (monomer 1) with β-propiolactone (monomer 2) and the structures of the resulting copolymers were studied. The copolymerization with sodium cyanide in N,N-dimethylformamide gave copolymers of the structure I containing acid anhydride linkage in the molecular chains, with the monomer reactivity ratios, r₁ = 1.20, r₂ = 0.00. The copolymerization with potassium hydroxide gave either copolymers of the structure II (r₁ = 0.00, r₂ = 3.64 at 30°C; r₁ = 0.00, r₂ = 5.00 at 40°C) in N,N-dimethylformamide or only β-propiolactone homopolymer in toluene.      

On the behavior of α-brominated dimethyl o-benzenediacetate toward nitrogen nucleophiles . Part I. Reaction of dimethyl α,α'-dibromo o-benzenediacetate with hydrazines

Meso- ( 1a ) and racemic dimethyl α,α'-dibromo o-benzenediacetate ( 1b ) when condensed with hydrazine and methylhydrazine furnished respectively 1,3-dicarbomethoxyisoindole ( 5a ) and its N-methyl derivative ( 5b ). Reaction of phenylhydrazine with 1a led to the N-phenylisoindole ( 5c ) and to the N-anilino isoindoline ( 6 ) as the cis isomer; conversely, 1b was transformed into a mixture of the 2-phenyl-1,2,3,4-tetrahydrophthalazine ( 7 ), the trans isomer of ( 6 ), the N-anilinoisoindole ( 5d ) and dimethyl α-(N'-phenylhydrazino)-o-benzenediacetate ( 8 ). Compounds 1a and 1b were also condensed with acetylhydrazine to give a mixture of the N-acetylaminoisoindoline ( 12 ) and of the 2-acetyl-1,2,3,4-tetrahydrophthalazine ( 13 ).     

Synthesis and antimicrobial activity of some 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones

The title compounds, 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been synthesized by reacting various 4‐hydroxy coumarins 1a , 1b , 1c with 2‐arylidene‐1‐tetralones 2a , 2b , 2c , 2d in the presence of ammonium acetate and acetic acid under Krohnke's reaction condition. The structures of all the synthesized compounds were supported by analytical, IR, ¹H‐NMR, and ¹³C‐NMR data. All the synthesized compounds 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been screened for their antibacterial activities against Escherichia coli (Gram ?ve bacteria), Bacillus subtilis (Gram +ve bacteria), and antifungal activity against Candida albicans (Fungi). J. Heterocyclic Chem., (2011).     

The reactions of perfluoro- and α,α-dichloropolyfluoroalkanesulfinates

Sodium perfluoroalkanesulfinate, R_FSO₂Na [R_F?Cl(CF₂)₄, 1a; CF₃(CF₂)₅, 1b; Cl(CF₃)₆, 1c] reacted with bromine in aqueous solution to give the corresponding sulfonyl bromide R_FSO₂Br (2a-2c) and in acetonitrile or acetic acid, to form perfluoroalkyl bromide R_FBr (3a-3c). Heating in acetonitrile at 80°C, 2a-2c were converted smoothly into 3a-3c. However, reaction of sodium α,α-dichloropolyfluoroalkanesulfinate RCCl₂SO₂Na (R?CF₃, Cl(CF₂)n, n=2, 4, 6, 5a-5d) with bromine in aqueous solution gave directly the corresponding bromoalkanes 1-bromo-1,1-dichloropolyfluoroalkane RCCl₂Br (6a-6d). In aqueous potassium iodide solution, 1a-1c, 5a and 5b also reacted with iodine to form the corresponding iodo-polyfluoroalkane 4a-4c, 7a and 7b directly. 6a and 7a underwent free radical addition to alkene readily in the presence of free radical initiator and reacted with Na₂S₂O₄ in the usual way to form α,α-dichloropolyfluoroethane sulfinate (5a). 5a was stable in strong acid, but reacted with strong base to yield 10. 5a was oxidised by hydrogen peroxide to the sulfonate 11 and reduced by zinc in dilute acid to from the α-chloro sulfinate 12.