Sultones substitution reactions

The formation of the sultone (160) probably involves addition of the complex across the alkene double bond, a 1,2-hydride shift and an intramolecular nucleophilic substitution reaction. The sultone (161) is formed by addition of sulfur trioxide to give the unstable p-sultone which rearranges to the more stable y-isomer (161). Another useful route to sultones is by metallation of alkanesulfonate esters for example, butane-1,3-dimethylsulfonate (162), prepared from butanel,3-diol, yields the 8-sultone, namely 6-methyl-l,2-oxathiin-2,2-dioxide (163) (Scheme 67). 

In addition to the regioselectively derivatized CDs, a number of statistically substituted CDs are in use. Highly water-soluble statistic derivatives are obtained by reaction of CDs with methyl halides [68], with epoxides (e.g., ethylene oxide, propylene oxide [69,70], or allyl glycidylether [71]), and with cyclic sulfates (e.g., butane sultone [72]). Statistical allyl ethers were converted to sulfonates by addition of sulfite [71], Monochlorotriazinyl-P-CD is another available reactive CD. Since these synthetic procedures are rather simple compared to the regioselective ones, many of these statistical compounds are available at the technical scale. 

P-Lactams 28 were obtained from reaction of acylhydrazones with chloroacetyl chloride . A -Alkylation of acridine derivatives with 1,3-propane sultone gave 29. P-Phenethylamides gave 3,4-dihydroisoquinolines and N-sulfonyl gave isoquinolines 30. Nucleophilic substitution of 4-bromoisoquinoline gave the corresponding 4-substituted isoquinolines. o-Bromobenzaldehyde was reacted with allylamine and then homophthalic anhydride to afford 31. ... 

Ciabattoni and Cabell224 reported that the reaction of mesylsulfene (from mesylmesyl chloride or a threefold excess of mesyl chloride) with tropone in the presence of triethylamine gave a tropone-mesylsulfene adduct (equation 137). Later, Truce and Lin225 found that a number of substituted sulfenes also add to tropone (equation 138) in a highly stereoselective fashion to form the corresponding y-sultones. 

In an attempt to obtain more information about the relative importance of bond breaking and bond making for reactions of sultones with nucleophiles, Williams and his coworkers measured the rates of reaction of phenoxide ion with a series of substituted 2-hydroxyphenylmethanesulphonic acid sultones together with the corresponding equilibrium constants (equation 104)149. From the Bronsted ftL and / Nu values the authors... 

On heating, the betaines formed from the reaction of propane sultone with tertiary amines have been found to undergo polymerisation (equation 111)167,168. Propane sultone reacts with substituted hydrazides to form sulphonic acids (equation 112)169. On the other hand, unsaturated -sultones react with hydrazides either on fusion or in a nonpolar solvent to form sultams as the major product (equation 113)169,170. In alcohols, either the corresponding sulphonic acids or hydrazine derivatives are obtained (equation 114). The unsaturated tricyclic -sultone 59 reacts with hydrazine to form the ethylpyrazole 60 (equation 115)171. Aliphatic sultones react almost quantitatively with potassium phthalimide108, and with the sodium derivative of amides (equation 116)163. 

It appears that SN reactions at saturated carbon atoms, free radical substitutions (again at saturated carbon) and S Ar reactions at unsaturated carbon have all been claimed to occur with aliphatic y- and -sultones, although documentation of evidence seems in some... 

Sultines, Sultones, and Related Systems.—A general synthesis of sultines (144) (cyclic sulphinate esters), based on the reaction of t-butyl hydroxyal-kyl sulphoxides (145) with SO2CI2 or N-chlorosuccinimide, has been developed. The method was shown to be suitable for the preparation of sultines varying in ring size from 5 to 8 and having a variety of alkyl or aryl substitution patterns. 

Overall, the constmction of sultones via sulfonylation/RCM from the corresponding allylic alcohol fulfills the requirements of an effective temporary tether in synthesis. The sultone functionahty provides sufficient reactivity under basic conditions to afford complex Z-substituted 1,3-dienols after the facile removal of the sulfonyl through the extrusion of SO2. The prospect of utilizing additional selective reaction pathways has the potential to generate new synthons furnishing a variety of pathways to biologically active natural products [8, 10]. 

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