Reagents for Final

Key reagents to products

TsCl, pyridine

Product: Alcohol, Tosylate R-OH, R-OTs (OH is a bad leaving group, OTS is a great leaving group, only changing the leaving group

1. TsCl, pyridine

2. NaCN

R-OH—> R- CN (SN2 major, inversion. CN replaces OTS TsCl makes a good leaving group → CN attacks.

PBr3

R-OH—> R- Br (substitution, SN2, inversion of stereochem, no carbocation forms

SOCl2

R-OH—> R-Cl (substitution, produces alkyl chloride, major product only

R: HX so any halogen (HCl, HBr, HI)

tert alcohol—> tert bromide (Usually SN1 (especially tertiary alcohols)

• Adds H + X

• X goes to the more substituted carbon

• H goes to the less substituted carbon

• Markovnikov

• No stereoselectivity

• Carbocation intermediate, so rearrangements are possible

Acid (H2SO4 or h30+) AND heat

OH—> Alkene + H20 (E1, possible carbocation rearrangments, forms more substituted (Zaitsev) alkene as major product

Lots of water

OH favored (Le Chaterlier’s principle) water pushes equilibrium toward alcohol

Heat

Alkene favored, heat removes water (shifts equilibrium toward elimination

OH ALONE

poor LG, Usually won't undergo SN1/SN2/E1/E2 until OH is converted into a better leaving group (like OTs or H2O).

1.BH₃·THF

2. H2O2, NaOH

alcohol (hydroboration-oxidation)

• Adds H + OH

• OH goes to the less substituted carbon

• H goes to the more substituted carbon

• Anti-Markovnikov

• Syn addition

• No rearrangements

OSO₄, H2O2 or KMnO₄, NaOH

Vicinal diol TWO OH groups on neighboring groups

One OH goes on each former alkene carbon.

• Adds OH + OH

• Syn addition

• No regioselectivity because both groups are OH

• The slides say you do not need the mechanism

H2 ·Pd. Pt. Ni

Alkane (adds H to each alkene carbon)

• Adds H + H

• Removes the π bond

• Syn addition

• No regioselectivity

Acid catalyzed hydration H20, H+, H30+

Alcohol (OH)

• Adds H + OH

• OH goes to the more substituted carbon

• H goes to the less substituted carbon

• Markovnikov

• No stereoselectivity: syn and anti products may form

• Carbocation intermediate, so rearrangements are possible

HBr, ROOR, heat or light

Alkyl Bromide

• Adds H + Br

• Br goes to the less substituted carbon

• H goes to the more substituted carbon

• Anti-Markovnikov

• No stereoselectivity

• Radical mechanism

• This special peroxide effect applies to HBr

X2 (Br₂, Cl₂)

Vicinal dihalide

That means one halogen is added to each of the two former alkene carbons.

• Adds X + X

• Anti addition

• No regioselectivity because both groups are identical

• Forms a halonium-ion intermediate

• No carbocation rearrangements

X2, H2O (Br₂, H₂O or Cl₂, H₂O)

Halohydrin

One alkene carbon receives OH, and the other receives X.

• OH goes to the more substituted carbon

• X goes to the less substituted carbon

• Anti-addition

• No rearrangements

• Hg(OAc)₂, H₂O

• NaBH₄

Oxymercuration-demercuration

Alcohol

• Adds H + OH

• OH goes to the more substituted carbon

• H goes to the less substituted carbon

• Markovnikov hydration

• According to these class slides, the new H and OH bonds are treated as anti

• No carbocation rearrangements because a mercurinium ion forms instead of a free carbocation

• Hg(OAc)₂, ROH (CH3OH)

• NaBH₄

Alkoxymercuration-demercuration

Ether:

• Adds H + OR

• OR goes to the more substituted carbon

• H goes to the less substituted carbon

• Markovnikov

• Anti relationship according to the class treatment

• No rearrangements

For methanol, the group added is OCH₃.