The first examples of successful allylsilane additions to chiral dipeptide aldehydes are described. Treatment of allylsilanes with tin tetrachloride at room temperature affords allyltrichlorostarnnane intermediates that reacts with dipeptide aldehydes to give 1,2-syn-homoallylic alcohols, potential intermediates for the synthesis of hydroxyethylene dipeptide isosteres. (C) 2001 Elsevier Science Ltd. All rights reserved.424171597162