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DOI: 10.1055/s-1996-5504
Synthesis of Alkenes with Pyramidalized Double Bonds - Unnatural Products of Theoretical Interest
Publication History
Publication Date:
31 December 2000 (online)
1,5-Transannular cyclooctane ring closure has proven to be a versatile entry into a variety of unnatural products that contain a [3.3.0]bicyclooctane moiety. This method has been used for the synthesis of [3.3.2]propellanes, but it has found its most important application in the synthesis of precursors of a homologous series of tricyclic, pyramidalized alkenes (8). Members of this series, in which chains of n methylene groups link C-3 and C-7 of bicyclo[3.3.0]oct-1(5)-ene, have been prepared with n = 0 - 3. In addition, a bis-ethano derivative of 8, n = 0, a benzo-bridged version of 8, n = 2, and a 10-selena variant of 8, n = 3, have been synthesized. The pyramidalized double bonds have been introduced either by β-lactone pyrolysis or by reduction of dihalide or dimesylate precursors. Several reactions that failed to give the desired products have also resulted in the serendipitous syntheses of interesting molecules and led to mechanistic studies of some of their chemistry. Other reactions that failed to give the expected products have stimulated both computational and experimental studies.
β-lactones - pyramidalized alkenes - reductive dehalogenation - transannular ring closure - unnatural products