Why are Grignard reagents prepared in excess?
1 Answer
Because (i) Grignards are reactive beasts that may be deactivated by adventitious water; and (ii) the excess reagent is destroyed during work-up, and removal of the excess is straightforward.
Explanation:
(i)
Water destroys the organometallic reagent. Sometimes we can isotopically label an organic species with
(ii) Since the product of water work up of excess Grignard is an alkane (most of the time), the excess can be easily removed by suction. It stands to reason that we use excess reagent to make the
