briefly-explain-why-ring-opening-takes-place-in-opposite-directions-in-the-react

Question

Briefly explain why ring opening takes place in opposite directions in the reactions shown below.

Diagrams of two reactions showing ring opening and carbocation stability in organic chemistry.

Accepted Answer

For Reaction 1, ring opening takes place in the indicated direction to avoid the formation of an unstable intermediate.
For Reaction 2, ring opening takes place in the indicated direction to form a stable carbocation intermediate.

Answer

For Reaction 1, ring opening takes place in the indicated direction because tetraalkylammonium group can stabilize positive charge.
For Reaction 2, ring opening takes place in the indicated direction because the ethoxy group is a weaker electron donating group compared to the tetraalkylammonium group.

Answer

For Reaction 1, ring opening takes place in the indicated direction because the tetraalkylammonium group is an electron donating group.
For Reaction 2, ring opening takes place in the indicated direction because an ethoxy group is an electron withdrawing group.

Answer

For Reaction 1, ring opening takes place in the indicated direction to form a stable carbocation intermediate.
For Reaction 2, ring opening takes place in the indicated direction to avoid the formation of carbocation intermediate.