Synthesis and reactivity of π-electron-dericient (arylsulfonyl) acetates

Different pi-electron-deficient (arylsulfonyl)acetates 9 were synthesized (Scheme 1, Table 1), and their behavior as soft nucleophiles in the dialkylation reaction under phase-transfer catalysis conditions was studied (Schemes 2 and 3. Tables 2 and 3). The [3,5-bis(trifluoromethyl)phenl]sulfonyl group was shown to be the best substituent for the stereoselective synthesis of (E)-aconitates 18 via an alkylation hydro-sulfonyl-elimination integrated process under very mild phase-transfer-catalysis conditions (Scheme 5. Table 4), Sulfonylacetes acetates 9h.i also underwent smooth Diels-Alder reactions with acyclic and cyclic dienes via in situ formation of the appropriate dienophile through a Knoevenagel condensation with paraformalclehyde (Scheme 6). Reductive desulfonylation with Zn and NH4Cl in THF was shown to be an efficient method for removal of the synthetically useful sulfonyl moiety (Schone 7).