Part 3. Which Reagents Go Together? (Step 1 vs. Step 2)

Oxymercuration–demercuration: which reagents are in step 1 and which are in step 2?

Step 1: Hg(OAc)2 and H2 O (together). Step 2: NaBH4 .

Hydroboration–oxidation: which reagents are in step 1 and which are in step 2?

Step 1: BH3 ·THF. Step 2: H2 O2 and NaOH (together).

Ozonolysis: which reagents are in step 1 and which are in step 2?

Step 1: O3 . Step 2: DMS (or Zn/H2 O).

Syn dihydroxylation with osmium tetroxide: which reagents are in step 1 and which are in step 2?

Step 1: OsO4 . Step 2: NaHSO3 and H2O (together). Alternative one-pot version: OsO4/NMO.

Anti dihydroxylation: which reagents are in step 1 and which are in step 2?

Step 1: RCO3H (mCPBA), which forms the epoxide. Step 2: H3O +, which opens it.

Which addition reactions use a SINGLE step (no 1) and 2) numbering)?

HX; HBr with ROOR; H3O +; H2 /Pt; Br2 ; Br2 /H2O; KMnO4 /NaOH (cold); OsO4/NMO; RCO3H (epoxidation).

An exam lists reagents alphabetically: BH3 ·THF; H2O2 ; NaOH. Which reaction is this and how are the reagents grouped?

Hydroboration–oxidation: 1) BH3 ·THF 2) H2O2 , NaOH. Anti-Markovnikov, syn addition of H and OH.

An exam lists reagents alphabetically: Hg(OAc)2 ; H2O; NaBH4 . Which reaction is this and how are the reagents grouped?

Oxymercuration–demercuration: 1) Hg(OAc)2 , H2O 2) NaBH4 . Markovnikov addition of H and OH, no rearrangement.

An exam lists reagents alphabetically: DMS; O3 . Which reaction is this and how are the reagents grouped?

Ozonolysis: 1) O3 2) DMS. Cleaves C=C into two C=O groups.

An exam lists reagents alphabetically: H3O +; RCO3H. Which reaction is this and how are the reagents grouped?

Anti dihydroxylation: 1) RCO3 H 2) H3O +. Gives a trans diol.

An exam lists reagents alphabetically: H2O; NaHSO3 ; OsO4 . Which reaction is this and how are the reagents grouped?

Syn dihydroxylation: 1) OsO4 2) NaHSO3 , H2O.