Ethers and Epoxides; Thiols and Sulfides

RX (an alkyl halide)

used for the alkylation of alcohols or thiols

1) Hg(OAc)₂, ROH
2) NaBH₄

achieve alkoxymercuration-demercuration of an alkene. This process adds H and OR in a Markovnikov fashion across the alkene.

HX

Will convert a dialkyl ether into two alkyl halides via cleavage of the C–O bonds. Will also react with an epoxide, thereby opening the ring, and installing a halogen at the more-substituted position.

MCPBA

An oxidizing agent that will convert an alkene into an epoxide.

RCO3H

An oxidizing agent that will convert an alkene into an epoxide

1) Br2, H2O

2) NaOH

An oxidizing agent that will convert an alkene into an epoxide (alternative)

NaOR

Can be used in a Williamson ether synthesis (reacts with an alkyl halide to form an ether) or to open an epoxide under basic conditions (the alkoxide ion attacks the less-substituted position).

RMgBr

Will react with an epoxide in a ring-opening reaction, to attack the less-substituted side

LiAlH4

It will react with an epoxide in a ring-opening reaction, to attack the less-substituted side

[H+], H2O (or H3O+)

Aqueous acidic conditions. Under these conditions, an epoxide is opened to give a trans diol

[H+], ROH

Under these conditions, an epoxide is opened, with a molecule of the alcohol attacking a protonated epoxide at the more-substituted position.

NaOH/H2O, Br2

Converts thiols into disulfides

HCl, Zn

Converts disulfides into thiols

H2O2

oxidizes sulfides to sulfoxides, and then further to sulfones

NaIO4

oxidize sulfides to sulfoxides