Reagent and Reaction Mechanisms

These flashcards cover key reagents and their reactions as discussed in the lecture.

PBr3 / SOCl2

Converts alcohol (OH) to halide with clean inversion and no rearrangement.

HBr / HCl on alcohol

Converts alcohol (OH) to halide through carbocation formation, allowing rearrangement.

H2SO4 + heat

Dehydrates alcohol (OH) to form an alkene via E1 mechanism, following Zaitsev's rule and potentially rearranging.

NaH

Deprotonates alcohol (OH) to form an alkoxide, setting up for Williamson ether synthesis.

NaOCH3, NaOEt

Reagents used in E2 elimination base reactions following Zaitsev's product preference.

KOC(CH3)3, NaOC(CH3)3

Bulky E2 bases that favor the Hofmann elimination (least substituted/terminal alkene) products.

NaOH

Serves as an SN2 nucleophile, converting halide to alcohol.

BH3 / R2BH

Hydroboration reaction that adds to alkenes anti-Markovnikov with syn addition and no rearrangement.

H2O2, NaOH

Oxidation step that replaces boron (B) in hydroboration with hydroxyl (OH).

Hg(OAc)2 + NaBH4

Oxymercuration reaction that adds OH in a Markovnikov fashion with no rearrangement.

mCPBA

Peroxyacid used to convert alkenes to epoxides with syn addition, resulting in racemic mixtures from achiral alkenes.

Br2, H2O

Bromohydrin formation where OH is added to the more substituted carbon and Br is added to the less substituted carbon.

O3 then Zn/(CH3)2S

Cleave alkenes to form two carbonyl compounds.

HgSO4/H2SO4/H2O on alkyne

Hydration of terminal alkynes yielding methyl ketones.

R2BH then H2O2/NaOH on alkyne

Anti-Markovnikov hydration of terminal alkynes producing aldehydes.

NaNH2

Deprotonates terminal alkynes to create acetylide nucleophiles.

Na, NH3

Dissolving metal reduction used to convert alkynes to trans alkenes.

H2, Lindlar

Poisoned palladium catalyst used to convert alkynes to cis alkenes.

LiAlH4 / NaBH4

Reducing agents that convert carbonyl compounds to alcohols.

PCC

Mild oxidizing agent that stops at aldehyde when converting primary alcohols.

Na2Cr2O7, H2SO4

Strong oxidation agent turning primary alcohols to carboxylic acids and secondary alcohols to ketones.

mCPBA

Converts alkenes to epoxides.