This reaction sequence involves several steps: 1. Formation of A (Grignard Reagent): Ethanol reacts with red phosphorus and iodine to form ethyl iodide which then reacts with magnesium in dry ether to form ethyl magnesium iodide (A). This is a Grignard Reagent which is very reactive. 2. Formation of B (Addition to Aldehyde): Ethylmagnesium iodide (A) reacts with formaldehyde (HCHO) to form a magnesium alkoxide intermediate (B). This addition reaction results in an increase in the carbon chain. 3. Formation of C (Acidification): Acidification of (B) leads to the protonation of the alkoxide intermediate which yields propanol(C). 4. Formation of D: No further reaction occurs as we get propan-1-ol (n-propyl alcohol). Conclusion: The major product D is n-propyl alcohol.
