Using the Fischer projection of (R) 2 butanol given in the margin, explain how each of the...

Using the Fischer projection of (R) 2 butanol given in the margin, explain how each of the following affects the configuration of the chirality center.

(a) Switching the positions of H and OH.

(b) Switching the positions of CH3 and CH2CH3.

(c) Switching the positions of three groups.

(d) Switching H with OH, and CH3 with CH2CH3.

(e) Rotating the Fischer projection 180° around an axis perpendicular to the page.

Sample Solution (a) Exchanging the positions of H and OH in the Fischer projection of (R) 2 butanol converts it to the mirror-image Fischer projection. The configuration of the chirality center goes from R to S.

Switching the positions of two groups in a Fischer projection reverses the configuration of the chirality center.