Synthesis of Vinyl Sulfones by Ring Opening of 4,4‐Dioxo‐2,3‐dihydrobenzo[b][1,4]oxathiines and Their In Situ Reactions with Nucleophilic or Electrophilic Agents

Abstract

A new, mild method of synthesis of 2-hydroxyphenyl vinyl sulfones from 4,4-dioxo-2,3-dihydrobenzo [b] [1,4]oxathiine derivatives is described. The products were further modified in situ, either by Michael addition of nucleophiles or by reaction of the 2-hydroxy group with an electrophile. The method can be utilized to immobilize proteins on a suitable support, or for other similar applications, as generation of the vinyl sulfone is always accompanied by formation of phenolate anion that can be used to bond in situ the vinyl sulfone to a suitable support.

The Synthesis and Base-Induced Breakdown of Triaryl 1,4-Oxathiins—An Experimental and DFT Study

“…One problematic reaction component had already been identified as unreacted starting material. Another reaction constituent was characterized as an acyclic breakdown product of the 1,4-oxathiin, a recognized fate that is frequently [15,16,41], but not always [22], observed when 1,4-oxathiins are treated with base. In this case, the structure of the ring-opened product was eventually assigned to be keto sulfone 7Z (vide infra).…”

“…This latter fate is presumed to lead to the undesired breakdown of the product. Variation of the aldehyde reactant created increased variability in the isolated yields (Table 1 # [11][12][13][14][15][16][17]. Heterocyclic furfural and thiophene-2-carboxaldehyde gave reduced yields (#17, 20); pyridine-2-carboxaldehyde did not yield any cyclized products.…”

“…During the early stages of the cyclization studies, the structure was assigned to be either 7E or 7Z since the availability of only one isomer did not permit a specific assignment. To pin down Variation of the aldehyde reactant created increased variability in the isolated yields (Table 1 # [11][12][13][14][15][16][17]. Heterocyclic furfural and thiophene-2-carboxaldehyde gave reduced yields (#17, 20); pyridine-2-carboxaldehyde did not yield any cyclized products.…”

“…The 1,4-oxathianes and -oxathiins have also been sought for access to acyclic targets [15,16] and as precursors to other heterocycles [17][18][19][20][21][22]. An oxathiin is an important component in a total synthesis of (+)-solamin [22].…”

“…The electrondeficient oxosulfine so formed can be re-captured via a hetero-Diels-Alder reaction to generate alternative 1,4-oxathiins 4-oxides [18,30]. The 1,4-oxathianes and -oxathiins have also been sought for access to acyclic targets [15,16] and as precursors to other heterocycles [17][18][19][20][21][22]. An oxathiin is an important component in a total synthesis of (+)-solamin [22].…”