Temperature-Independent Stereoselectivity in Intramolecular Cycloaddition of Ketene Generated from Diazoester in Solution and in Vapor Phase: How Entropy Term Governs the Selectivity
The intramolecular [2 + 2] cycloaddition between alkene and ketene linked with 2,4-pentanediol tether was performed in a wide range of temperature, −60 to +400 °C. When the ketene was generated by ...
The first vaporphase asymmetric synthesis was successfully carried out by FVP of a 2,4-pentanediol (PD)-tethered substrate carrying cyclohexene and diazo ester moieties at high temperature up to 400°C. The intramolecular [2+2] cycloaddition of the ketene was strictly stereocontrolled by the entropy term.