Progress in the synthesis of δ-sultones

Abstract

Sultones, the cyclic esters of hydroxyl sulfonic acids, are a fascinating class of heterocycles and the recent years have witnessed an increasing interest in these molecules, especially in six-ring δ-sultones. The importance of these compounds is either because of their biological properties themselves or due to their versatility as intermediates in more complex target syntheses. Accordingly, the development of new synthesis methods to access δ-sultones is an important and rewarding task which we wish to highlight in this review.Graphical abstract

Updating the CSIC Reaction (2003–2020)

“…However, by searching reviews for "sultones", typical CSICr products, we were confronted with the fact that some authors using and describing CSICr did not apply our proposed name reaction. This is the case of Gaunersdorfer and Waser [6] in a recent review describing the progress on the synthesis of δ-sultones, when instead of using "CSICr" they wrote: "…of enolate-type nucleophilic addition reactions to access differently ring-sized sultones have been reported in the past, either via cyclization/addition of sulfonate-based carbanions to an adjacent electrophilic position (e. g., an ester or an aldehyde)…". [6] However, Xu and colleagues (reference 12 in Waser's review) used and cited the CSICr without complexes and prejudices.…”

“…This is the case of Gaunersdorfer and Waser [6] in a recent review describing the progress on the synthesis of δ-sultones, when instead of using "CSICr" they wrote: "…of enolate-type nucleophilic addition reactions to access differently ring-sized sultones have been reported in the past, either via cyclization/addition of sulfonate-based carbanions to an adjacent electrophilic position (e. g., an ester or an aldehyde)…". [6] However, Xu and colleagues (reference 12 in Waser's review) used and cited the CSICr without complexes and prejudices. [7] Other authors neglected also the new name reaction to figure it: "…Aldol-Type Condensations and Related Processes…On the other hand, the intramolecular condensations of alkanesulfonates, derived from cyanohydrins, in the presence of different bases lead directly to β-amino α,β-unsaturated γ-sultone…", [8] or were totally reluctant to use the CSICr name, [9] still preferring the aldol reaction name, even in transformations using simple, non-carbohydrate precursors [10] following years later the original and pioneering approach proposed by Marco-Contelles [1,11] to extend the scope of the original sugar-like CSICr discovered by Gómez de las Heras et al [4] Then, since the beginning it was clear for us that a full survey of the real progresses of CSICr would be a difficult task, almost impossible.…”

Synthesis of Novel α,β-Unsaturated Sulfonic Acid Derivatives Containing Dithiocarbamate/Xanthate Groups by Ring Opening of an α,β-Unsaturated γ-Sultone

“…1,2 Sultones can react with a wide variety of nucleophiles, with cleavage of the C-O bond to introduce alkanesulfonic acid or sulfonate functions into complex molecules, thus behaving as sulfoalkylating agents. 3,4 Although the chemistry of saturated sultones is well investigated, synthetic applications of unsaturated sultones especially ,-unsaturated -sultones are much less well studied. These unsaturated sultones can act as sulfoakenylating agents in organic synthesis.…”