Tricyclic sultone

A six-step synthesis of nonactic acid with excellent stereocontrol via sultone intermediates has been published (Scheme 26) <1998EJO2073>. The tricyclic sultone 107 was synthesized by a tandem esterification/cycloaddition with vinylsulfonyl chloride whereby only the fvo-adduct with fvo-Me was obtained <1989AGE202>. Next, the tandem elimination/alkoxide-directed 1,6-addition first led to a mixture of sulfones, but equilibration with catalytic... 

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. 

Majumdar et al. reported tricyclic sultone derivatives starting from unactivated vinylic systems by the implementation of the palladium-catalyzed... 

Cava and Schlessinger have reported the synthesis of 1,2,3-triphenyl-isoindole (65) in 78% yield from 1,3-diphenylisobenzofuran (68) hy reaction with thionylaniline (69) and boron trifluoride. The mechanism proposed for this remarkable transformation involves reaiTangement of the adduct (70) derived from thionylaniline and the isobenzofuran, to the tricyclic intermediate (71). This presumably collapses to the S-sultam (72), which yields the isoindole (65) upon extrusion of sulfur dioxide. Loss of sulfur dioxide, both from S-sultones and unsaturated S-sultams, is well documented. ... 

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