Tamoxifen is a selective estrogen receptor modulator (SERM) widely used in the treatment and prevention of estrogen receptor–positive breast cancer. Structurally, it is a triphenylethylene derivative, consisting of a substituted alkene framework connecting three aromatic rings, along with a basic side chain. … Read more
Have you seen your professor talking about BH₃ and H₂O₂ and not quite understood what it is and when to use it?Ok, so, keeping it simple, we use BH₃ together with a peroxide to place an OH group on the … Read more
Amides are the least reactive derivatives of carboxylic acids, so reducing them requires using the strong reducing agent LiAlH4. The reduction converts primary, secondary, tertiary cyclic, and acrylic amides to corresponding amines: The Mechanism of Amide Reduction by … Read more
Carboxylic acids can be reduced to primary alcohols using an excess of strong reducing agents such as lithium aluminum hydride (LiAlH4 or LAH). As sodium borohydride (NaBH4) is the most common reducing agent we learn about together with … Read more
Alkynes and nitriles are structurally similar, so let’s discuss how we can replace one of the carbons in the alkyne with a nitrogen: When one of the carbons is replaced, the carbon chain will be shortened by one. … Read more
In the previous post, we saw that amides can be reduced to amines by LiAlH4: Let’s see how tertiary amides can be reduced to amines and aldehydes using alkyboranes. Reduction of Amides by Alkylboranes The reduction of amides … Read more
Alkynes to Ketones Alkynes can be converted to aldehydes and ketones via hydration reactions such as 1) Acid-Catalyzed Hydration, 2) Oxymercuration-Demercuration, and 3) Hydroboration-Oxidation. The first two are used for Markovnikov conversion of terminal alkynes to ketones, whereas the hydroboration-oxidation … Read more
Hydroboration-Oxidation of Alkynes Like alkenes, alkynes can also be subjected to Hydroboration-Oxidation to achieve an anti-Markovnikov addition of an OH group to the π bond. As in the case of acid-catalyzed hydration and oxymercuration, the intermediate here is an enol, which, this … Read more
The Regiochemistry of Hydroboration-Oxidation In the previous post, we mentioned that Hydroboration-oxidation places the OH group on the less substituted carbon of an alkene: There are two reasons for this: steric and electronic. This is a result of … Read more
Hydroboration-oxidation converts alkenes into alcohols: THF (tetrahydrofuran) is the solvent that is used to stabilize the BH3, which otherwise tends to form a dimer, B2H6 – a flammable, toxic, and explosive gas: It is a few-step … Read more
