Question

From the reactions shown, A and B respectively are:

• A. A: vinyl chloride; B: ethanol in acid (catalytic)
• B. A: methyl magnesium bromide + work up; B: methanol in acid (catalytic)
• C. A: allyl bromide; B: ethanol in acid (catalytic)
• D. A: vinyl magnesium chloride; B: ethanol in acid (catalytic)

Answer 1

The correct option is B

A: methyl magnesium bromide + work up; B: methanol in acid (catalytic)

A denotes a Grignard addition while B denotes the formation of an acetal:
For the Grignard addition, $C{H}_{3}MgBr$ followed by work up (separate) gives:

For the acetal formation,