Un nouveau thiénobenzopyrane à propriétés vasodilatatrices cérébrales: le 9b-hydroxy-3-phényl-1,3,3a,9b-tétrahydro-4H-thiéno[3,4-c]benzo[e] pyrane-1-carboxylate d'éthyle

Reaction of 3,3-dialkyl-6-trifluoromethyl-2,3-dihydro-4-pyrones with alkyl mercaptoacetates. Synthesis of derivatives of 2-oxa-7-thiabicyclo[3.2.1]octane

“…Thus, we have demonstrated that dihydropyrones 1 and 2 behave similarly to α,β-unsaturated ketones 3,4 and react simultaneously with alkyl mercaptoacetates at the double bond and carbonyl group without cleavage of the pyran ring. The above reaction is simple and results in the formation of a bridged 2-oxa-7-thiabicyclo[3.2.1]octane system that has been obtained for the first time and is worthy of further investigation.…”

“…It has previously been demonstrated 3 that interaction of alkyl mercaptoacetates with α,β-unsaturated ketones proceeds via nucleophilic addition of the mercapto group to an activated double bond with further cyclization at the carbonyl group leading to the corresponding thiophane derivatives. A similar reaction of ethyl mercaptoacetate with 3-benzylidenechroman-4-one 4 gives ethyl 9b-hydroxy-3-phenyl-1,3,3a,9b-tetrahydro-4Hthieno [3,4-c]benzo[e]pyran-1-carboxylate, and with esters of aryl-5 and polyfluoroalkyl 6 propiolic acids regioisomeric 3-hydroxythiophenes are formed.…”