Strategies in Spiroketal Synthesis Revisited: Recent Applications and Advances

Over the course of the last several decades, a number of strategies have been designed for synthesizing spiroketals stereoselectively. This review looks at selected highlights of these strategies as they relate to recent synthetic efforts directed at natural products. While particular emphasis will be given to some newer strategies and innovations, examples of many of the strategies described herein have been documented in previous reviews. In these cases, recent applications of these established methods will be described. Sections will be categorized according to strategy, and not natural product or spiroketal ring size. Reference to the same natural product may therefore be found in different sections. Finally, a section will be included which reviews examples of recentlyreported reactions of spiroketals.