7. Substitution Reactions

Suggest a mechanism for the following substitution reactions.

(d)

For each reaction, give the expected substitution product, and predict whether the ­mechanism will be predominantly first order (SN1) or second order (SN2).

c. 1-iodo-1-methylcyclohexane + ethanol

For each solvent, indicate the most likely substitution reaction to take place.

(e)

Predict the product of the following substitution reactions, making sure to note whether a rearrangement should occur.

(c)

Would you expect the following conditions to favor S_N1 or S_N2?

(b)

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (i) SOCl₂ ; (ii) PBr₃ ; (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; (v) 1. TsCl, Et₃N 2. NaOt-Bu (vi) H₂SO₄ (vii) HCl; (viii) HBr; (ix) PCC; (x) H₂CrO₄ , H₂O (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(o)

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (vii) HCl; (viii) HBr; If no reaction occurs, write 'no reaction.'

(o)

Predict the major products of the following substitutions.

a.

Draw the substitution products for each of the following S_N2 reactions. If the ­products can exist as stereoisomers, show which stereoisomers are formed:

c. (3R,4R)-3-bromo-4-methylhexane + CH₃O^-

d. (3R,4S)-3-bromo-4-methylhexane + CH₃O^-

Predict the product of the substitution reactions, paying attention to the stereochemical outcome.

(a)