Ring-rearrangement metathesis of substituted dihydropyrans and dihydrofurans

The rearrangement of dihydropyrans and dihydrofurans featuring appending olefins has been studied. The rearranged products bear resemblance with polyunsaturated di- and trisaccharides. Examples of functionalization prior to, or following, rearrangement are provided suggesting that the method should be useful for the synthesis of nonclassical saccharides. This work also illustrates the power of cascade methatetic processes for increasing molecular complexity starting from relatively simple heterocycles.     

Design and synthesis of oxa-bowls via Diels–Alder reaction and ring-rearrangement metathesis as key steps

Ring-rearrangement metathesis of norbornene derivatives prepared by Diels–Alder reaction has been used to design various oxa-bowls. Enyne ring-rearrangement metathesis of norbornene ring systems with propargyl moiety produced diene containing oxa-bowls, suitable for further expansion by Diels–Alder strategy.     

Extended RCM-ROM sequences: a novel approach to polyunsaturated trisaccharides

The first examples of RCM-ROM-RCM-ROM-RCM sequences involving non-strained heterocyclic relays are described. The method can be used for the preparation of polyunsaturated trisaccharides.     

Synthesis of 2,6-dioxabicyclo[3.3.0]octenes by tandem ring-rearrangement/cross metathesis

A facile synthesis of stereodefined 2,6-dioxabicyclo[3.3.0]octene derivatives from the vinyl ether of endo-7-oxanorbornen-2-ol via tandem ring-opening/ring-closing(ring-rearrangement)/cross metathesis is reported.     

Ring-rearrangement metathesis of 3,6-dialkoxy-3,6-dihydro-2H-pyrans

The first RCM-ROM-RCM sequence using a non-strained heterocycle as relay moiety is described. The course of the reaction strongly depends on the nature and relative configuration of the substituents in the starting trienic system. In addition, for a productive reaction to be observed, the site of initiation of the metathesis cascade is crucial. The compounds thus obtained may be useful for the synthesis of unusual polydeoxydisaccharides.     

Application of ring-rearrangement metathesis in organic synthesis: A grand design

In this report, we compiled various strategies involving a ring-rearrangement metathesis as a key step to assemble diverse molecules. Popular name reactions such as Grignard reaction, Overman rearrangement, Fischer indolization, Beckmann rearrangement and Diels–Alder reaction were used in combination with ring-rearrangement metathesis to construct complex targets. Additionally, CH activation and RRM strategy has been used to assemble azacycles. In some instances, the ring-rearrangement metathesis was expected to occur; however, ring-opening metathesis products were realized. These methods were included in the miscellaneous section. We anticipate that the lessons learned here are useful in designing complex polycyclic and heterocyclic targets suitable for biological and material science applications. Beside our work, we have also included others work as a background information.