Synthesis, X-ray crystal structure, equilibration studies and anion chemistry of trans-1,3-dithiane 1,3-dioxide

The Chemistry of C2‐Symmetric Bis(sulfoxides): A New Approach in Asymmetric Synthesis

“…[15] On this substrate, best conditions for the reaction and the isolation were devised by Aggarwal et al and of all the oxidants, sodium periodate in methanol was found to be the most selective in favour of 2. [16] This stabilization would originate from a favourable electrostatic interaction from the axial sulfoxide bent to the equatorial sulfoxide, [10] as confirmed by an X-ray structure determination. This was confirmed by molecular mechanics calculations, indicating a bonus of stabilization of 0.8 kcal·mol Ϫ1 for the trans isomer.…”

“…All these pK a measurements were carried out in DMSO by Bordwell et al and disclosed by Aggarwal et al for 2, 3 [10] and 5 [65] and, herein by us, for 43 and 44. All these pK a measurements were carried out in DMSO by Bordwell et al and disclosed by Aggarwal et al for 2, 3 [10] and 5 [65] and, herein by us, for 43 and 44.…”

“…All these pK a measurements were carried out in DMSO by Bordwell et al and disclosed by Aggarwal et al for 2, 3 [10] and 5 [65] and, herein by us, for 43 and 44. [10] The structure of the bis(sulfinyl)methyl anions has been investigated and has revealed a trigonal structure. The latter example was rationalised by the reduced dipole moment of 2 compared to 3, originating from the dipole stabilization displayed in Scheme 1.…”

“…[13,14] Running the reaction in cyclic series generally renders the job easier and a lot of efforts have been oriented toward the oxidation of 1,3-dithiane (1) (Scheme 1). [16] This stereoselectivity is governed by ''product-development control'', [17,18] suggesting that the trans isomer is the more stable one. [16] This stereoselectivity is governed by ''product-development control'', [17,18] suggesting that the trans isomer is the more stable one.…”

“…This was confirmed by molecular mechanics calculations, indicating a bonus of stabilization of 0.8 kcal·mol Ϫ1 for the trans isomer. [16] Scheme 1 In his extensive studies, Aggarwal et al also showed that the cis isomer 3 could be isomerized to 2 with N 2 O 4 [19] and that for 5,5-dimethyldithiane, the cis-disulfoxide was always obtained as the major compound, except with ozone (trans/cis ϭ 58:42).…”