Exploitation of Aryl Synthons in the Synthesis of Polycyclic Natural Products

A brief review is provided of procedures developed in the author's laboratories which enhance the value of aromatic synthons used in the synthesis of alicyclic target compounds. The methodology is concerned principally with the intramolecular ipso-alkylation of aryl moieties initiated by a protonated diazoacetyl function, and metal-ammonia reductions of aromatic carboxylic acids, esters and ketones. 1. Introduction 2. Early History 3. Applications of Intramolecular ipso-Alkylations to Diterpene Synthesis 4. Diazoketone Cyclisations With Subsequent Rearrangements 5. Intramolecular Rhodium(II)-Catalysed Cyclopropanations of Aryl Rings 6. Birch Reductive Alkylations of Methoxybenzoic Acids 7. Birch Reductive Alkylations of Benzoic Esters 8. Birch Reductive Alkylation of Aromatic Ketones 9. Conclusion