Fenestranes in Synthesis: Unique and Highly Inspiring Scaffolds

The scaffold of fenestranes is quite unique, as it contains four condensed cycles and a distorted tetracoordinated central carbon atom with bond angles greater than the regular 109°28“. In this Minireview, a detailed overview on the developments regarding this compound class, including their synthesis, is given for the time period since 2006. In the past years, natural products that belong to the class of heterofenestranes have been isolated and their syntheses will also be discussed. Highly strained: Four condensed cycles and a distorted tetracoordinated carbon center with bond angles greater than the regular 109.4° make the scaffold of fenestranes quite unique. A definition and nomenclature of these scaffolds is followed by a detailed overview over recent syntheses of these strained molecules, including their impact on the study of planar tetracoordinate carbon atoms.