The titanium(IV)-mediated cyclopropanation of ethyl beta -chloropropionate by Grignard reagents and in situ tosylation, followed by base-induced dehydrochlorination provided diastereoselectivity pure (E)-2-alkyl-1-ethenyl-1-(tosyloxy)cyclopropanes. suitable precursors of 1,1-ethyleneallylmetal species of significant synthetic potential. (C) 2001 Elsevier Science Ltd. All rights reserved.