Answer:
See explanation and image attached
Explanation:
The reaction between (R)-2-bromooctane and -CN^- is an SN2 reaction. An SN2 reaction involves a synchronous attack of the nucleophile as the leaving group is departing.
This leads to a five member transition state in which a bond is being broken and another is being made. Since the nucleophile attacks from the backside, SN2 mechanism leads to inversion of configuration as shown in the image attached.