Question

Assign R or S configuration to the following molecule, write the product you would expect from S_N2reaction with NaCN, and assign R or S configuration to the product (green = Cl):

Short answer

The product expected from S_N2 reaction with NaCN and assigning of R/S configuration is,

Step-by-step solution

SN2 reaction with NaCN

NaCN is a strong nucleophile inS_N2reaction, and it replaces the halogen group.An inversion of configuration at the chiral centre occurs; if it is S configuration, it changes to R configuration.

The alkyl bromide from which alkyl acetate is made by SN2 reaction

The substrate with an S configuration has a secondary allylic chloride group, and a hydroxyl group is primary. AS_N2 reaction occurs at the secondary carbon and gives R cyano product because OH is a poor leaving group.

Product expected from S_N2 reaction with NaCN