(1) From the above analysis, it can be seen that the structural formula of cinnamaldehyde F is:, e is, and the names of oxygen-containing functional groups are: hydroxyl and aldehyde groups, so the answer is:; Hydroxyl group, aldehyde group;
(2) The reaction that accords with atomic economy is addition reaction. Among the questions, ① is an addition reaction, ② is an oxidation reaction, ③ is a substitution reaction, ④ is an oxidation reaction, ⑤ is an addition reaction and ⑤ is an elimination reaction, which is in line with atomic economy, so the answer is: ①;
(3) Reaction ⑥ is the elimination reaction; The chemical equation of reaction 4 is:, so the answer is: eliminate the reaction; ;
(4) The isomer of E () satisfies that there are two substituents on the benzene ring, one of which is methyl in the para position and belongs to ester, and the qualified isomer is:, so the answer is:.