(4+3)Cycloaddition Reactions Cycloaddition of Metal Oxyallyl Cations Generated from alph,alpha'-Di- and alph,alpha'-Poly-Haloketones to 1,3-Dienes and Anthracenes

The (4+3)cyclocoupling reaction of allyl cations to 1,3-dienes is an efficient and easy route for the stereoselective synthesis of seven-membered ring compounds. Annulations using these species have opened easy access to a wide range of organic frameworks that have been utilized in the synthesis of natural products, pharmacologically active compounds and key intermediates for various useful organic and alkaloid compounds.