2-sulfonyl aldehydes, hydrogenation

Alkyl sulfonyl chlorides, having an a-hydrogen atom, react with enamines derived from aldehydes and cyclic ketones in the presence of triethylamine to give cyclic sulfones. Thus the enamine (22) gave the four-membered cyclic aminosulfone (143) on reaction with methanesulfonyl chloride (95). 

An acidic solution of 2,4-dinitrophenylhydrazine reacts with N-p-chlorophenyl-sulfonyl-3-ethoxy-l,2-thiazetidine 1-oxide to give (80%) the bis-2,4-dinitrophenyl-hydrazone of glyoxal. The adduct of A-sulfinyl-p-chlorophenylsulfonamide with dihydropyran is inert to catalytic hydrogenation and bromination. Treatment of two l,2-thiazetidine-3-one 1-oxides (e.g., 421) with hydriodic acid results in ring-cleavage and loss of sulfur. They are not oxidized to 1,1-dioxides by peracetic acid, ° but m-chloroperbenzoic acid accomplishes this oxidation. The unstable adducts with ketene decompose to amides with loss of hydrogen sulfide and sulfur dioxide or may be trapped by reaction with aromatic amines as shown for thiazetidine 1-oxide 422.An aldol-type condensation has been reported for A -cyclohexyl-1,2 thiazetidine-3-one 1-oxide and p-(A(A"-dimethylamino)benz-aldehyde. " Sulfur monoxide is lost in the flash-vacuum thermolysis of 422a. ... 

It may rather be that in the case of third row substituents like R4P the relative acidity of cyclopropyl and isopropyl hydrogens is not as indicative of the carbanion configuration as in the case with the second row substituents C(0)R, CN and possibly NO2. As far as cyclopropyl sulfones are concerned one would therefore predict that the corresponding a-sulfonyl cyclopropyl anions may have a pyramidal configuration. The deprotonation of cyclopropyl phosphonates, followed by reaction with aldehydes, was recently published by Hirao and coworkers ... 

Higher -chlorinated sulfonyl chlorides616 can be prepared in good yield by saturating aldehydes with hydrogen sulfide and treating the product with chlorine in the presence of water. 

No reaction occurs under these conditions with esters, acid chlorides, acid anhydrides, azobenzene, sulfones, and sulfonyl chlorides. The following groups evolve hydrogen but do not undergo reduction alcohols, phenols, carboxylic acids, amides, and sulfonic acids. Aldehydes and ketones are reduced to alcohols, and N,N-dimethylamides to aldehydes. F. e. s. H. C. Brown and D. B. Big-ley, Am. Soc. 83, 486 (1961). 

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