Investigation on Novel Reactions of Oxabenzonorbornadienes and Cyclopropanated Oxabenzonorbornadienes

Abstract

The present work demonstrates the first examples of carboxylic acid-tethered cyclopropanated oxabenzonorbornadienes (CPOBDs) to undergo ring-opening reactions in mild acidic conditions. Two regioisomers are formed but the reactions are highly regioselective towards type 3 ring-opened products. It was observed that substitution at the C-5 and aryl positions of CPOBD significantly hinders the ring-opening reactions leading to poor yields of ring-opened product, although high regioselectivity for the type 3 ring-opened product is still maintained. The second part of this thesis outlines a study on the regio- and stereo-chemistry of the iridium-catalyzed hydroacylation of C1-substituted OBDs with salicylaldehyde. The scope of the reaction was expanded to include various electron-donating, electron-withdrawing and bulky substituents to investigate the electronic and steric effects of the C1- substituent on the hydroacylation reaction. It was observed that the addition occurred exclusively at the less hindered, C3 position to give the corresponding adducts.