Medium-sized (in particular 8-membered) rings are important architectural features in a variety of biologically active substances (e.g. taxoides) and there are only a few universal methods to target them. Cycloaddition, rearrangements, or direct cyclization reactions are the most predominant approaches. Samarium diiodide-induced cyclizations via ketyl intermediates are a promising, highly regio- and stereoselective possibility to access such ring systems. This methodology is especially attractive as it is functional-group compatible and starting materials are readily available from simple and inexpensive building blocks allowing for a wide range of modifications.
展开▼
