5.21 Consecutive sigmatropic rearrangements

Complex natural products are a great source to foster creativity and innovation in organic chemistry. Although efficient and reliable methods to construct C-C, C-N, and C-O bonds have been developed, the rapid assembly of architecturally complex molecules still remains a formidable challenge. Over the last two decades, the sigmatropic rearrangements have benefited from thorough mechanistic study. In addition, the use of sigmatropic rearrangements in domino processes along with their stereochemical outcome predictability provides an attractive and powerful strategy to construct complex scaffolds. In this chapter, the authors describe a wide variety of sigmatropic rearrangements that involve two or more consecutive transformations. As one can anticipate, [3,3]-sigmatropic shifts will cover a large section in this chapter