Jmol animations

Stereospecific E2 eliminations - two diastereoisomeric bromides give two different geometric isomers of alkene.

Play the animation. Zoom in and take a closer look

Manipulate the model to explore the arrangements of the protons and the bromine. Are they antiperiplanar as required for E2?

Play the animation to rotate the central C-C bond. Using the frame next button, manipulate the model to see the two Antiperiplanar possibilities. Can you arrange the model to mimic the Newman projections?

Note the spatial relationship of the two phenyl groups leading to Z- and E-alkenes.

Examine the animated energy plots of S,R-Diastereoisomer and R,R-Diastereoisomer to determine the relative energies of the antiperiplanar conformations required for E2 elimination and hence understand the rate difference.