Identify D in the following sequence of reactions: [figure]
- n-propyl alcohol
- isopropyl alcohol
- propanal
- propionic acid
Answer
(1) n-propyl alcohol
Solution
Red P and I2 convert ethanol to the iodide:
CH3CH2OH P + I2 CH3CH2I (A)
which forms the Grignard reagent with Mg:
CH3CH2I [dry ether]Mg CH3CH2MgI (B)
This adds to methanal,
CH3CH2MgI + HCHO CH3CH2CH2OMgI (C)
and hydrolysis gives the alcohol:
CH3CH2CH2OMgI H2O CH3CH2CH2OH + Mg(OH)I
A Grignard reagent with methanal gives a primary alcohol, so D = n-propyl alcohol.
Answer: (1)