THE 7,8-EPOXY2,3,5,6-TETRAKIS(METHYLENE)BICYCLOOCTANE; SYNTHESIS AND DIELS-ALDER REACTIVITY

Article abstract of DOI:10.1016/0040-4020(80)85037-X

The preparation of 7,8-epoxy-2,3,5,6-tetrakis(methylene)bicyclo<2.2.2>octane (5) is described.Evidence for transannular interaction between the homoconjugated s-cis-butadiene functions in 5 is found in the UV absorption spectrum.The Diels-Alder addition of 5 to tetracyanoethylene (TCE) is syn-regioselective and leads to the monoadducts 16:17 (85:15).The dienes 16, 17 are less reactive then 5 toward TCE. anti-regioselectivity (leading to exo-2, endo-3-bis(chloromethyl)-5,6-bis(methylene)-syn-7,8-epoxybicyclo<2.2.2>octanes) (25) is observed in the double elimination of HCl from the syn-7,8-epoxy-exo-2,endo-3,exo-5,endo-6-tetrakis(chloromethyl)bicyclo<2.2.2>octane (11), precursor of 5.The structure of the regioisomers 16, 17 were confirmed spectroscopically and chemically.Elimination of HCl from the chloromethyl groups in 26 (TCE adduct of 25) and HCN from the TCE adducts 16, 17 and 26 can be induced by CsF in DMF.