Sulphonic acid anhydrides

There is still opportunity for further enlightenment in the interpretation of chemical shifts of thiosulphonates, particularly with reference to sulphonic acids, anhydrides and esters. 

Thirdly, using the new heats of formation suggested by BBGW, one may readily deduce that homolysis reaction 42 is some 115kcalmol-1 exothermic. However, given that this reaction is also favourable entropically and requires but the cleavage of a single bond, it is hard to reconcile it with any of the other reactions of sulphonic acid anhydrides known to the current author. 

Unhindered thiolesters give excellent yields of symmetrical carboxylic acid anhydrides when oxidized with ozone. However, with hindered thiolesters, mixed carboxylic acid-sulphonic acid anhydrides are obtained in good yield. Steroidal alcohols may be converted into the corresponding fluorides, albeit in variable yields, with Et2NSF3. ... 

Exposure of the ethylidene diacetate to an aromatic sulphonic acid in the presence of five times its weight of acetic anhydride as diluent at 136°C will yield the following mixture 40% vinyl acetate 28% acetic acid 20% acetic anhydride 4% ethylidene diacetate 8% acetaldehyde. 

When azulene is heated with sulphuric acid and acetic anhydride a sulphonic acid, soluble in water, is formed. This acid forms a fine violet sodium salt. This sodium salt is not very stable when kept for three months it decomposes into a mixture of oil and resin. Its aqueous solution gives blue precipitates with calcium and barium salts. 

It should be noted that of the four main mechanisms described above, reversal of the first two suggests that the rate-determining step in desulphonation takes place upon the sulphonic acid, whereas in the latter two mechanisms, it will take place upon the anhydride. 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

Formation.—When sulphur dioxide is passed into ice-cold fuming nitric acid, crystals of nitrosulphonic. acid separate.1 The acid is also obtained when sulphuric acid is treated with excess of nitrogen peroxide.2 It is also formed by the interaction of sulphur dioxide and nitrogen peroxide both in the absence or presence of water,8 and by the addition in equimolecular proportion of liquid nitrogen tetroxide to chloro-sulphonic acid in the absence of moisture.4 Sulphuric acid acts on either nitrous anhydride or nitrosyl chloride with formation of nitrosulphonic acid, according to the equations ... 

Preparation 491.—Diazobenzenesulphonic Acid Anhydride (Inner salt of bcnzenediazonium-hydroxide-i-sulphonic Acid). 

Nitriles Some amides, Sulphonic acids, Esters. Anhydrides. hydrocarbons. hydrazo and other... 

A further route to compounds with an aromatic ring A lies in an unusual acid-catalysed rearrangement of steroidal A -3-ketones. Testosterone (35) is reported to give the 4-methyl aromatic compound (36) with trichloroacetic anhydride in the presence of toluene- -sulphonic acid [178]. The mechanism of this reaction is not clear. 

A group of reactions involving 16,17-epoxy-pregnane derivatives illustrates the facility of C(is) methyl migration to an electron deficient C(i ). The i6a,i7a-epoxypregnan-20-ones (13) react with acetic anhydride and toluene- -sulphonic acid [24], hydrogen fluoride [23], and other acidic reagents [23,26], to form i7a-acetyl-i7/5f-methyl-i8-nor-olefins (14) and (15). The preferred position of the double bond apparently... 

Cholest-4-en-3 One and its enol acetate are converted into the 6-sulphonic acid derivative by sulphuric acid in acetic anhydride. This, and other sulphonation reactions, are consistent with the presence of a reactive sulphonating species in the solution [100]. 

Effects of adding safts on nitration in sulphuric acid Nitric acid and trifluoromcthanc sulphonic acid Nitric acid and hydrofluoric acid Nitric acid and phosphoric acid Nitric acid and acetic anhydride... 

The mechanism of the reactions involved in the synthetic process for preparing this compound has been explained by Heymann (Berl. Ber. 1891, p. 3066). The yellow solution resulting from the action of the sulphuric anhydride on phenyl-glycine contains the sulphonic acid of indoxyl-sulphuric ester. On dilution of this solution, oxidation is effected by the sulphuric anhydride. 

Compound (80), prepared from 2-methylcyclopentane-l,3-dione and methyl 2-chloroacrylate followed by the sequence (76)-> (77)-> (78)- (79) (resolved)— (80), combined with (71) (prepared from m-methoxyphenylstyrene and diborane) to form the seco-steroid (82)/ Acetic anhydride-toluene-p-sulphonic acid then cyclized this stereoselectively to furnish the triacetate (83) which on saponification gave the triol (84). Interestingly, this compound reacted with toluene-p-sulphonic acid in alcohol to produce, by dehydration and change of configuration at C-14, the compound (85), which served as a source of various 8a-oestrone compounds. Compound (84) on treatment with boron trifluoride etherate underwent pinacol transformation in preference to dehydration to yield the ketone (86) this ketone was correlated with the known compound (87). 

Bonds to Oxygen.—Compounds of Lower Oxidation State. Mixed sulphur-phosphorus anhydrides result when sulphonic acids and dialkyl hydrogen phosphites react according to equation (17).448 Further work on the preparation of trimethylsilyl esters of phosphorous acids has been carried out by... 

The Chemistry of Rii% b.— The 9— 6p lactone (44, R = H) of the 12-methoxy-podocarpa-8,ll,13-triene series was obtained by the successive dehydration of the 7a- and 7)3-hydroxy-lactones with toluene-p-sulphonic acid in acetic anhydride and hydrogenation of the resulting A -enol-lactone over palladium-charcoal. Examination of the width of the C-6 proton resonance led to the... 

Dehydration of the 10)8-hydroxy-5/ -methyl compound (560) (toluene-p-sulphonic acid-acetic anhydride) gave the product (561) in high yield, but the corresponding 6-ketone (562) rearranged less readily, giving also the AUio).ene (563). In neither case was any A -compound formed, indicating that... 

In contrast to the usual reaction of aromatic aldehydes with cyclic ketones o-nitrobenzaldehyde condenses with 17-ketones to produce good yields of seco-acids, a reaction which has been applied to the preparation of 16-oxa-steroids. Thus, 3 -hydroxy-5a-androstan-17-one or its acetate affords the seco-steroid (153), which can be oxidised either as the free acid by ozone and alkaline hydrogen peroxide to the diacid (155) or, as its methyl ester (154), with chromium trioxide to the monomethyl ester (156). Diborane reduction of the diacid (155) or lithium aluminium hydride reduction of the dimethyl ester (157) gave the trans-diol (158), cyclised with toluene-p-sulphonic acid to 16-oxa-androstan-3)5-ol (159) or, by oxidation with Jones reagent to the lactone (152) (as 3-ketone) in quantitative yield. This lactone could also be obtained by lithium borohydride reduction of the monomethyl ester (156), whilst diborane reduction of (156) and cyclisation of the resulting (151) afforded the isomeric lactone (150). The diacid (155) reacted with acetic anhydride to afford exclusively the cis-anhydride (161) which was reduced directly with lithium aluminium hydride to the cis-lactone (160) or, as its derived dimethyl ester (162) to the cis-diol (163) which cyclised to 16-oxa-14)5-androstan-3) -ol (164). 

The 2, 19-epoxydienone (372) has been prepared by the action of acid or base upon either the fluoro- or chloro-19-acetates (371), which were obtained by halogenation of the oxalyl derivative of (370) and subsequent cleavage of the 6/5,19-oxide ring with acetic anhydride-toluene-p-sulphonic acid. 

---