Draw the major nucleophilic substitution product of each reaction below, showing stereochemistry when necessary. Circle which mechanism type, Snl or Sx2, each reaction proceeds by. You do not need to show the mechanisms. CI Но- Syl or a. Sn2 Br SN1 or NANH2 SN2 b. DMSO SN1 O Na or Br Acetone Sn2 с.

21. Provide all possible E2 products with the correct stereochemistry. Label the major elimination product. Br NaOCH3

Draw the product X of the following SN2 reaction. X was a key intermediate in the synthesis of rizatriptan, a drug introduced in 1998 for the treatment of migraines.

DMSO 1. KBr + KOt-Bu major product 2. Na NaCl a = Electrophilic addition d = SN2 Nucleophilic substitution g= Nucleophilic subs at carbonyl(acyl Xfer) h = Conjugate (nucleophilic) addn b = E2 Elimination e Electrophilic aromatic substitution f = Carbonyl nucleophilic addn c = SN1 Nucleophilic substitution Identify the mechanism by which each of the reactions above proceeds from among the mechanisms listed. Use the letters i for your answers. 1 2. + Hot-Bu