Presentation is loading. Please wait.

Presentation is loading. Please wait.

Pericyclic Reactions (McM chapt 30)

Similar presentations


Presentation on theme: "Pericyclic Reactions (McM chapt 30)"— Presentation transcript:

1 Pericyclic Reactions (McM chapt 30)
Polar react. (nucleophiles and electrophiles) Radical react. Pericyclic react. (concerted, cyclic TS#) Electrocyclic react. Cycloadditions (i.e. Diels Alder) Sigmatropic rearrangement Rearrangement of polyene Termal (react. in ground state) or photochemical (react of exited state)

2 Symmetry Allowed React.
Woodward Hoffmann rules Symmetry in reactants are preserved during pericyclic react. Results can generally be predicted just by looking at Front Orbitals (FMO; HOMO and LUMO) - Fukui

3 Molecular orbitals 1,3-butadiene Stereospesific react. S: Symmetric
A: Antisym.

4 Molecular orbitals hexatriene Symmetry allowed react

5 Photochemical electrocyclic react.

6 Cycloadditions (i.e. Diels Alder)
Stereospesific react.

7 endo - exo selectivity Normal electron demand DA - Electron poor dienophile (Michael accept.) Ethene etc, very low react. Michael accept. Lower LUMO

8 [2+2] Cycloadditions

9 Carbene Cycloadditions

10 Sigmatropic Rearrangements
[3,3] Rearrangements; Claisen rearrang. etc.

11 [1,5] Rearrangement (H-shift)


Download ppt "Pericyclic Reactions (McM chapt 30)"

Similar presentations


Ads by Google