Hexatriene sulfur dioxide addition

The first synthesis of thiepin 1,1-dioxide (131) was performed by Mock in 1967 75>. With exess bromine in chloroform 2,7-dihydrothiepin 1,1-dioxide (129), prepared by 1,6-addition of sulfur dioxide to m-hexatriene, gave a dibromide 130 which, on treatment with two equivalents of triethylamine, afforded 131. Upon catalytic reduction, 131 rapidly absorbed three molar equivalents of hydrogen to yield hexahydrothiepin 1,1-dioxide (132). The 1,1-dioxide 131 is a fairly stable compound ... 

A double nucleophilic substitution reaction on 1,6-dibromohexane with sodium sulfide has been found to give an acceptable yield (59%) of the thiepane (35 equation 62) (81SC409). The reversible 1,6-addition of sulfur dioxide to ds-hexatriene (equation 63) provides a convenient synthetic route to the 2,7-dihydrothiepin 1,1-dioxide (116) (67JA1281). 

Diels-Alder reaction. Sulfur dioxide adds 1,6 to cu-hexatriene in ether at room temperature to form the adduct 2,7-dihydrothiepin-l,1-dioxide (2).2 The reaction is analogous to the 1,4-addition of sulfur dioxide to butadiene (see Sulfolene, this... 

---

See also in sourсe #XX -- [ , ]

---