Synthetic and theoretical aspects of the meta-cycloaddition

• Main Author: Javed, Sahar
• Format: Dissertation
• Language: English
• Published: University of Reading 2012

Since its discovery in 1966 the alkene-arene meta-photocycloaddition reaction has proved useful in the total synthesis of several natural products and compounds of theoretical interest. [I] Introduction of a complex tricyclic carbon framework to afford the commonly observed regioisomers 1 and 2 (Scheme i) via a single step is achieved upon irradiation of an aromatic and alkene precursor with 253.7 nm light. The reaction is of significant utility and has been subject to various mechanistic studies leading to the proposal of a widely accepted mechanism. More recently, high level theory has been applied to the prototypical case of benzene and ethene, however, the affect of substituents upon this model remains to be examined. providing scope for investigation in this area. Herein an approach to maximise the chemical and quantum yields in the intramolecular version of the reaction will be studied as a foundation towards the total synthesis of natural products containing a gomerane skeleton (Figure i).[4] Such syntheses will be directed using ab initio electronic structure calculations in a predictive manner to establish regio- and stereochemical preferences, enabling the utility of computational methods to be assessed in a field of considerable synthetic importance.