Question

2. c. (15 pts) Explain briefly alongside each pair of structures why it is easier to form an acetal from molecule A than molecule B in each pair. F3CCF, H3C CH3

Answer 1

In first pair, the molecule B is more bulky and it is difficult for alcohol to attack the carbonyl carbon. So molecule A is more likely to form acetal.

% heme OH 0 11 Meot OH = oh, ome X © meOH 0 1 hemiacetat IL MO + mon c ome lome MeOH i me Hot Home O. of onome umeon meget one I - 10 I (8)

In second pair, the molecule B have electron withdrawing - CF3 groups which make the carbonyl carbon more electron deficient by decreasing the electron density on carbonyl carbon and make it more easy for the alcohol to attack on carbonyl carbon. In molecule B, there is - CH3 groups which is electron donating, make the carbonyl carbon more electron rich, thus make less likely to form acetal.

In third pair, the ring strain in molecule A make it more likely to form acetal. In molecule B there is less ring strain. So molecule B is less likely to form acetal.