Cycloadditions and Related Reactions

Methacryhc acid and its ester derivatives are Ctfjy -unsaturated carbonyl compounds and exhibit the reactivity typical of this class of compounds, ie, Michael and Michael-type conjugate addition reactions and a variety of cycloaddition and related reactions. Although less reactive than the corresponding acrylates as the result of the electron-donating effect and the steric hindrance of the a-methyl group, methacrylates readily undergo a wide variety of reactions and are valuable intermediates in many synthetic procedures. 

Fallis A. G., Lu Y. F. TT-Facial Diastereoselection in Diels-Alder Cycloadditions and Related Reactions Understanding Planar Interactions and Establishing Synthetic Potential Adv. Cydoaddit. 1993 3 1-66... 

The first step of the reaction sequence is the addition of the nucleophilic anion to position 8a of the starting salt 34 to give an intermediate 37 which rapidly undergoes nitrogen elimination to yield the zwitterionic product 38 as a relatively stable brilliant red crystalline substance in high yield. The strong dipolar character of 38 allowed further transformations via 1,3-dipolar cycloadditions and related reactions <2003JOC5652>. 

Figure 2.61 Carbonyl compounds as well may react with in 1,3-dipolar cycloadditions and related reactions.

CONTENTS Facial Diastereoselection in Diels-Alder Cycloadditions and Related Reactions Understanding Planar Interactions and Establishing Synthetic Potential, A. G. Faille and Yee-Fung Lu. Substituent and Structural Effects in the Ozonolysis of Cyclic Vinylogous Esters. W. H. Bunnelle. N-Metalated Azomethine Ylides, S. Kanemasa and Otohiko Tsuge. Azomethine Ylide Cy-cloadditlons via 1,2- Prototropy and Metallo-Dipole Formation from Imines, R. Grigg and V. Sridharan. Index. 

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