Thietane-l-oxides

The stereochemistry of 3-substituted thietane-l-oxides (5) has been investigated by NMR and it was found that the sulphinyl oxygen atom occupies the axial position preferentially at equilibrium. This has been attributed to the hydrogen-oxygen attraction as shown in Scheme... 

Treatment of 3-hydroxythietanes 21b-g with aqueous sodium hydroxide led to retro-aldol ring cleavage to produce the carbonyl derivatives 23b-g (Table 1) <1997J(P2)425>. It was proven that the rate of the reaction was determined by the nature of the substituent at the 3-position and by the oxidation state of sulfur. 3-Phenylthietane-3-ol 21b underwent retro-aldol reaction to give sulfide ketone 23b. Thietane-l-oxide-3-ol 21c-e or thietane-l,l-dioxide-3-ol 2 If and 21g derivatives underwent retro-aldol reaction to produce carbonyl sulfoxides 23c-e and carbonyl sulfones 23f and 23g (Table 1) <1997J(P2)425>. 

The Pummerer reaction of 2,3-di(benzoyloxymethyl)-thietane-l-oxide 34 with 6-chloropurine in the presence of TMSOTf in toluene led to the modified thietanyl chloropurine 35 (Equation 8) <1999TL7385>, which after the subsequent action of ammonia resulted in a modified adenosine. 

The mechanism proposed for the reduction of thietane 1-oxide by hydrogen sulfide is complex the order of reactivity is ethyl methyl sulfoxide > thiolane 1-oxide > diethyl sulfoxide > dimethyl sulfoxide > thietane l-oxide. ... 

Thietan l>Oxides, Thietan 1,1-Dioxides, and Thiet 1,1-Dioxides... 

Small Ring Compounds of Sulphur and Selenium 9 Thietan l-Oxides... 

A -Thietane 1-oxide, 3-methyl-3-phenyl-l-(p-tolylsulfonimino)- C NMR, 7, 414 (80JOC4807)... 

Cyclization of y, -unsaturated sulfenic acids to give thietan 1-oxide derivatives. Crystal structure of rei-(l/ ,2S,3/ ,4/ )-3-hexyl-2-hydroxy-methy 1-4-methylthietan 1 -oxide. ... 

An efficient and easy method for oxidation of thietane to thietane A-oxide uses nitric acid in the presence of P2O5 supported on silica gel, under solvent-free conditions <2005TL5503> the use of l-butyl-4-aza-l-azoniabicyclo[2.2.2] octane dichromate (BAAOD) in refluxing MeCN is also very efficient for this transformation <2003PS2441>. 

The basicity of the sulfoxide oxygen has been investigated by observing infrared shifts in protic solvents. ° In this way, it was shown that thietane 1-oxide is more basic than cyclobutanone, but less basic than tetramethylene sulfoxide (thiolane 1-oxide) or pentamethylene sulfoxide (thiane l-oxide). ° Toward phenol, the order of basicity is as follows thiolane 1 -oxide > diethyl sulfoxide > thiepan 1-oxide > dimethyl sulfoxide > thiane 1-oxide > 9-thiabicyclo[3.3.1]nonane 9-oxide > 7-thiabicyclo[2.2.1]heptane 7-oxide > thietane 1-oxide.ThepKaof the conjugate acid of thietane 1-oxide is — 1.92, as determined in aqueous sulfuric acid. =... 

Tetramethyl-3-thietanone 1-oxide 400 is obtained in 69% yield by oxidation of the thietane with peracetic acid in benzene. Amides of 3-thietanone-2,4-dicarboxylic acid 1-oxide are said to be obtained by treatment of amides of acetone dicarboxylic acid with thionyl chloride and 3-thietanone-l-oxides may be intermediate in the reaction of ketones with thionyl chloride. The -oxide of 3,3,4,4-tetraphenyl-2-thietanone may be an intermediate in the oxidation of the thietanone by nz-chloroperbenzoic acid, which is discussed in Section XIII.4.E. ... 

The ligands at sulphur in thietan 1-oxides, - - thietan-l-toluene-p-sulphonylimides, 5 -methylthietanium ions, and S -methoxythietanium... 

Heats and enthalpies of oxidation of cis- and trans-3-t-butylthietan 1-oxides to the 1,1-dioxides by perlauric acid at 298 K have been determined. The structures of cis-2,4-diphenylthietan l-oxide and the seven-co-ordinate complex of 3,3-dimethylthietan 1-oxide with the shift reagent Eu(dpm)3 have been established by X-ray analysis. The mass spectrum of thietan 1-oxide shows fragmentation to CsHs and... 

The addition of sulfenic acids to olefins207 has been successfully applied in the synthesis of thietanoprostanoids, the thietane analogues of prostaglandin245. The general synthetic scheme is presented in equation 83207. The key step is the thermolysis of either erythro- or (7ireo-2-f-butylsulphinyl-3-vinyl-l-ol (209) to give the corresponding alkenesulfenic acids 210, which cyclize spontaneously to a mixture of stereoisomeric thietane oxides. 

Application of the enamine-sulfene cycloaddition allowed the synthesis of 78 and 79 from the corresponding a,/l-unsaturated amines and sulfenes. Similarly, using enamine 80, the crystalline morpholino thietane dioxides (81) were produced. Elimination via the N-oxide gave the corresponding thiete dioxide, whereas reduction by LiAlH4 yielded the thietane 82. 

Whereas oxidation leaves the fused thietane derivative 218 intact by giving the corresponding sulfone, reduction produces the 4-isopropyl-l,l-diphenyl-bicyclo[4.1.0]hept-l-ene (219) by extrusion of sulfur (Eq. 58). The general oxidation procedure to convert thietanes to their sulfones comprises refluxing with peracetic acid. 

---