Towards acyclic 1,1-linked polycyclobutanes as potential precursors of polyspiranes with a helical primary structure: Synthesis of tercyclobutanes and attempted synthesis of quinquecyclobutanes

Acyclic 1,1-linked polycyclobutanes 1 should be potentially prone to rearra nge to polyspiranes with a helical primary structure. In an exploratory stu dy, the synthesis of die tercyclobutanes 8 (5-6-7-8) and 15 (9-10-11-12-16- 15 or 14-15), and several approaches to quinquecyclobutanes with the beta- and delta-ketoesters 35 (15-33-34-35) and 24b (23-24a-24b). respectively, a s most promising precursors are described. (C) 1999 Elsevier Science Ltd. A il rights reserved.