Acyl anion equivalents. Synthesis of ketones and α-(phenylthio)ketones from the adducts of bis(phenylthio)carbanions and carbonyl compounds

Synthesis and olfactory evaluation of allylic α‐quaternary thioether ketones

“…Although thioenol ethers are less reactive than enol ethers, the peculiar ability of sulfur to stabilize the cationic charge on the adjacent carbon was expected to facilitate the rearrangement of suitably substituted diallyl alcohols . Sulfur‐mediated semipinacol rearrangements are quite rare and have been reported mainly for ring expansion reactions of dithioacetals . Some rearrangements involving aromatic vinyl sulfides have been devised, and a singular case of a five‐membered ring expansion involving an alkyl vinyl sulfide has been reported .…”

Photoredox‐Mediated Synthesis of β‐Hydroxydithioacetals from Terminal Alkynes

“…An important class of sulfur containing molecules viz., dithioacetals and their various oxides have served as versatile tools in organic synthesis [3] . Particularly, they are used to protect the carbonyl group against nucleophilic attack as they can be easily deprotected to their parent aldehydes or ketones [4] Moreover, these can be further functionalized into a variety of products ranging from arylthioepoxides to α‐arylthioketones [5] . Moreover, unsymmetrical substituted acetylenes and olefins can be accessed through dithioacetals [6] .…”

Cycloelimination of β-silylethyl sulphoxides: alkene, alkyne, and vinyl-silane-forming reactions

“…As far as we are aware, this has never been observed, although the corresponding selenoxide eliminations have been reported.lS In reviewing the literature forming reaction. on this subject, we discovered that no one seemed to have given this type of reaction a fair chance; the compounds tested had always had alternative reactions available to them.16 Accordingly, we heated the sulphoxide (21), and found that the major product was the isomeric sulphoxide (23). Almost certainly this was…”

“…produced by an acetylene-forming elimination (21)+ ( 22), followed by a readdition ( 22)+ (23), with the regioselectivity known for that reacti0n.l' However, the readdition was so fast and efficient that we were unable to detect the acetylenic intermediate (22). In contrast, the p-silylvinyl sulphoxide (24) cleanly gave the acetylenic ketone (25) at 120 "C; evidently the silyl sulphenyl ester does not consume the product.…”

“…The sulphoxide (21) (2 mmol) (as prepared above) in toluene (5 ml) was heated under reflux at 120 "C under argon for 1.5 h. Evaporation under reduced pressure followed by column chromatography (diethyl ether-light petroleum, 1 : 1 as eluant) gave ethyl 3-phenylsul~hinylpropenoate (23) (ca. 60y'), RF 0.27 (diethyl ether-light petroleum, 1 : l ) , vmax.…”