organic chem test 3

polar protic solvents

water, methanol, ethanol, ammonia, acetic acid

“watch my elephant after animals”

polar aprotic solvents

Acetone, HMPA, Acetonitrile, DMF, DMSO

“Always help after day doors”

strong bases, weak nucleophiles

NaH, DBN, DBU, KOtBu (hoffman)

strong bases, strong nucleophiles

OH, MeO, EtO

weak bases, strong nucleophiles

I-, Br-, Cl-, RS-, HS-, RSH, H2S

weak bases weak nucleophiles

H2O, MeOH, EtOH

what reaction has reagants: BH3THF, H2O2, OH

hydroboration-oxidation (anti markovnikoc and syn addition)

what reaction has reagants: H2SO4, H2O

acid catalyzed hydration (markovnikov, rearrangement possible)

what reaction has reagants: Hg(OAc)2, H2O, NaBH4

oxymercuration-demercuration (markovnikov, no rearrangement)

what reaction has reagants: HBr, ROOR

radical addition (anti markovnikov)

what reaction has reagants: Br2, H2

halohydrin formation (OH and Br added, OH→ more substituted carbon)

what reaction has reagants: Br2

halogenation (2 Br atoms add anti)

what reaction has reagants: excess Br2

depends→ can add 4 Br

what reaction has reagants: O3, Me2S

reductive ozonolysis (breaks C=C bond into carbonyl compound)

what reaction has reagants: NaH

strong base→ often forms alkoxide/anion

what reaction has reagants: KOtBu

bulky base→ favors Hoffman product

what reaction has reagants: NaOEt, EtOH

strong base/nucleophile → favors Zaitsev E2

what reaction has reagants: TsCl, pyridine

tosylation (converts OH into LG)

what reaction has reagants: NaSH

strong nucleophile weak base → favors substitution to form C-SH

3 mechanisms to make an alcohol

1. hydroboration

2. acid catalyzed hydration

3. oxymercuration-demercuration

hydroboration-oxidation

converts alkene to alcohol

anti- markovnikov

O and OH added to same face (syn addition)

SN2 reactions

stereoinversion at carbon where substitution occured

one step

backside attack

strong nucleophile

acetic acid structure- polar protic

acetone structure- polar aprotic

dimethylsulfoxide (DMSO) structure- polar aprotic

dimethylformamide (DMF) structure- polar aprotic

acetonitrile structure- polar aprotic

E2 reactions

strong base

beta H removal

double bond formation

one step

naming alkenes

-ene

parent chain will be longest chain WITH C=C bond

the greater number of carbon groups attached to C=C…

more stable the alkene

which is more substituted- hoffman or zaitsev product

zaitsev

bulky base (NaOtBu and KOtBu) favor which product

Hoffman

position of beta H and LG for E2 mechanism

must be anti conformation

strong bases weak nucleophiles

NaH, DBN, DBU, KOtBu (hoffman)

strong bases strong nucleophiles

OH-, MeO-, EtO-

weak bases strong nucleophiles

I-, Br-, Cl-, RS-, HS-, RSH, H2S, CN-

weak bases weak nucleophiles

H2O, MeOH, EtOH

which reaction mechanism: strong base weak nucleophile with 1 prime substrate

E2

which reaction mechanism: strong base weak nucleophile with 2 prime substrate

E2

which reaction mechanism: strong base weak nucleophile with 3 prime substrate

E2

which reaction mechanism: strong base strong nucleophile with 1 prime substrate

mostly SN2, some E2

which reaction mechanism: strong base strong nucleophile with 2 prime substrate

mostly E2, some SN2

which reaction mechanism: strong base strong nucleophile with 3 prime substrate

E2

which reaction mechanism: weak base strong nucleophile with 1 prime substrate

SN2

which reaction mechanism: weak base strong nucleophile with 2 prime substrate

SN2

which reaction mechanism: weak base strong nucleophile with 3 prime substrate

SN2

which reaction mechanism: weak base weak nucleophile with 3 prime substrate

SN1/E1

strong nucleophiles favor ____ weak nucleophiles favor ____ (depending on base strength)

substitution

elimination

P-toluenesulfonyl (Ts) structure

pyridine- base structure

what reactions do Ts and pyridine favor

substitution