Michael addition of methyl 2-(trimethysily)propenoate with organomagnesiums or organolithiums leading to 1:1 and / or 2:1 adducts and subsequent peterson olefination by condensation with carbonyl compounds

Michael addition of methyl 2-(trimethylsilyl)propenoate with organomagnesiums or organolithiums leads to 1:1 and/or 1:2 adduct anions which can be utilized in the subsequent step of Peterson olefination with carbonyl compounds. The 1:1/1:2 ratio depends upon the nature of donor molecules, the reaction conditions such as reaction temperature, polarity of solvent, and rate of addition of the acceptor molecule. Use of acceptors in excess results in the selective formation of 1:2 and/or 1:3 adducts.