Dimethyl 3-methylglutaconate:: a useful reagent for the diastereoselective synthesis of functionalized 5,6-dihydro-2H-pyran-2-ones

Condensation of dimethyl 3-methylglutaconate with aldehydes leads to the formation of 6-substituted 5,6-dihydro-2H-pyran-2-ones through aldolisation followed by cyclization. The conditions of the aldolisation reaction in order to increase diastereoselectivity are described. Chiral aldehydes and aminoaldehydes have been used. The 6-substituted 5,6-dihydro-2H-pyran-2-ones prepared from aminoaldehydes could be interesting protease inhibitors. (C) 1999 Elsevier Science Ltd. All rights reserved.