Greig I R, Tozer M J, Wright P T
James Black Foundation, 68 Half Moon Lane, Dulwich, London, SE24 9JE, UK.
Org Lett. 2001 Feb 8;3(3):369-71. doi: 10.1021/ol006863e.
[figure: see text] Substituted 2,3,3a,4,5,7a-hexahydrobenzo[d]isothiazole 1,1-dioxides and 3,4,4a,5,6,8a-hexahydro-2H-benzo[e][1,2]thiazine 1,1-dioxides, novel cyclic sulfonamides, were synthesized by the thermal Diels-Alder reaction of triene derivatives of buta-1,3-diene-1-sulfonic acid amide. The stereochemical outcome of the reaction was determined by NMR spectroscopy and X-ray crystallographic analysis. This chemistry has been used for the synthesis of 2-(4-chlorobenzyl)-5-(1H-imidazol-4-yl)-2,3,3a,4,5,7a-hexahydrobenzo[d] isothiazole 1,1-dioxide, a histamine H3 receptor antagonist.