Synthesis and rearrangement of dispiro[2.0.3.4]-, dispiro-[3.0.3.3]- and dispiro[2.1.3.3]undecanes-preferred C4-C5 over C3-C4 and C4-C3 over C5-C6 rearrangements

Article abstract of DOI:10.1016/S0040-4020(01)85700-8

The dispiranes 10-12 have been synthesized and rearranged by treatment with acids. With 10, an initial C₃-C₄ ring enlargement leads to [3.3.3]propellane 21, with 11, an initial C₄-C₃ ring contraction leads to pe