The Zipper-Mode Domino Intramolecular Diels–Alder Reaction: A New 0→ABCD Strategy for Steroids and Related Compounds We thank Dr. Simon Fielder (HortResearch New Zealand) and Mr. Leon Wong (University of Sydney) for preliminary experiments, Dr. Kelvin Picker (University of Sydney) for assistance with HPLC and GC analyses, and Dr. Ian Luck (University of Sydney) for 2D NMR experiments. This work was supported by The Australian Research Council and The University of Sydney.
bonds, four rings, and eight contiguous stereocenters in one go! Tetracyclic product 2, which results on warming simple acyclic precursor 1 with a mild Lewis acid, is formed through an efficient and highly stereoselective domino sequence of two intramolecularDiels-Alder reactions. Pharmacologically important norsteroids are just one potential application of this extremely effective approach to fused