Toshiyuki Hamura, Michiko Kakinuma, Shinsuke Tsuji, Takashi Matsumoto, and Keisuke Suzukià Department of Chemistry, Tokyo Institute of Technology and CREST, Japan Science and Technology Corporation (JST), O-okayama, Meguro-ku, Tokyo 152-8551 ... Dichlorocyclobutenone acetals, available via the cyclo- addition of dichloroketene and alkynes followed by acetalization, undergo selective SN2' attack by various nucleophiles to give a variety of ...