Chem 348 Exam 2 reactions

makes markovnikov’s product with no reaarangments

produces racemic mixture

Oxymercuration/reduction of alkenes

1.Hg (OAC)₂, H₂O
2.NaBH₄

Sterospecific for syn, makes anti-markovnikov products

Hydroboration/oxidation of alkenes

1.BH₃, THF OR 9-BBN

2.H₂O₂, NaOH

Syn addition. H’s are added on the same face

Hydrogenation of alkenes

1.H₂

2.Pd/C

substituents are placed via if the molecule is cis vs trans. if meso, no EN, if cyclic then the O is wedged/ dashed

Epoxidations with peroxyacids

mCPBA

DCM

1) draw anti-alcohol

2) draw wedges and dashes for substituents

3) check for EN by flipping

if cyclic the oh just adds onto anti faces

for cis draw substituents on same face, if trans draw substituents on different faces

Anti-dihydroxylation

1.mCPBA

2. H₃O

Add substituents based on cis or trans

if meso , no EN

NMO is used by facilitating catalytic cycle

(regenerates OsO₄ so reaction can continue)

Syn-dihydroxylation

OsO₄

NMO

Reductive workups make aldehydes

Ozonolysis (reductive workup)

1) O₃,CH₂Cl₂

2) Zn, HOAC OR DMS

oxidative conditions make carboxylic acids

Ozonolysis (oxidative workup)

1) O₃, CH₂Cl₂

2) H₂O₂

adds chorine to different faces if cyclic, the substituents for regular alkene depend on original cis vs trans

Addition of dichlorocarbene

KOtBu, CHCl₃

TBuOH or THF

stereochemistry is dictated by original orientation ( cis vs trans)

Simmons-smith rxn

CH₂I_2, Zn (Cu)

Et₂O

produces AM product

vinyl<1<alkyl<benzylic (most stable)

radical additions of alkenes

HBr

ROOR

Produces AM product

radical addition of HBr

HBr

(BzO)₂ OR AIBN

double bond is not removed and is added to allylic position. remember that radical can be shifted around

Allylic bromination

NBS

hv, CCl₄

needs cis/trans retainment

goes to alkane

Catalytic hydrogenation of alkyne

H₂

Pd

only produces cis products

Hydrogenation of alkyne with lindlars cat.

H₂

Lindlars cat.

produces trans alkene

dissolving metal reduction of alkynes

Na or LI

NH₃ @ -78 degrees C

produces a methyl ketone attached to the more substitued carbon (Markovnikov)

oxymercuation of alkynes

HgSO₄

H₂O, H₂SO₄

anti-markov product producing either aldehyde or keton

Alkyne hydroboration

1. 9-BBN

2. H₂O_2,NaOH

attached to either side of triple bonded carbons

alkyne alkylation

1. LDA

2. methyl or 1 degree halide