- Pt, B: Electron movements in acid-base reactions can be represented with the same curvedarrow notation. a) Be sure you understand the defined roles of a Lewis acid and a Lewis base. b) Show the reaction of the Lewis acid FeCl3 with an acetal using curved-arrow notation (acetals are an ether-like functional group that you will learn more about in (342). c) What orbitals were involved in the chemistry you just described? [You should give the orbital in terms of its hybridization, the independent property of whether it is filled/halffilled/empty, and its relative energy (e.g., highest energy filled orbital). Do you think certain types of orbitals are likely to be involved in Lewis acid-base interactions? d) Now show how one of the C.O bonds is weakened allowing the methyl-bearing carbon to be attacked by a nucleophile