During your synthesis of a compound, an S_(N)1 reaction (about which you will learn more later) resulted in partial racemization of your chiral center, which you could tell because the specific rotation of the product was different from the starting material. What is the reason for this partial racemization?
1) The reaction proceeded through an intermediate with a planar chiral center, allowing for inversion of stereochemistry.
2) The reaction proceeded through an intermediate with a planar chiral center, allowing for retention of stereochemistry.
3) The reaction proceeded through an intermediate with a tetrahedral chiral center, allowing for inversion of stereochemistry.
4) The reaction proceeded through an intermediate with a tetrahedral chiral center, allowing for retention of stereochemistry.