Abstract The treatment of 4-chlorobutyronitrile, 3-chloropropyl phenyl sulfone, and other related compounds with a base afforded γ-halocarbanions that undergo fast intramolecular substitution of the halogen to produce substituted cyclopropanes. We found that these short- lived carbanionic intermediates can be trapped with active external electrophilic partners, such as aldehydes, to give the aldol anions. These anions then undergo rapid ...
