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Please name the two most common methods to prepare primary alcohols from aldehydes and describe the reaction mechanism for one of them.

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The two most common methods to prepare primary alcohols from aldehydes are:1. Reduction using metal hydrides, such as sodium borohydride  NaBH4  or lithium aluminum hydride  LiAlH4 .2. Catalytic hydrogenation using a metal catalyst, such as palladium on carbon  Pd/C  or platinum on carbon  Pt/C , and hydrogen gas  H2 .I will describe the reaction mechanism for the reduction using sodium borohydride  NaBH4 :1. Sodium borohydride  NaBH4  is a reducing agent that can donate hydride ions  H-  to the carbonyl carbon of the aldehyde. The boron atom in NaBH4 has a negative charge and is bonded to four hydrogen atoms. This makes it a good source of hydride ions.2. In the first step of the reaction mechanism, the hydride ion  H-  from NaBH4 attacks the electrophilic carbonyl carbon of the aldehyde. This results in the formation of a new carbon-hydrogen bond and the breaking of the carbon-oxygen double bond   bond .3. Simultaneously, the electrons from the carbon-oxygen double bond move to the oxygen atom, creating a negatively charged alkoxide intermediate.4. In the final step, the alkoxide intermediate abstracts a proton  H+  from a solvent molecule  usually water or an alcohol , which leads to the formation of the primary alcohol product.Overall, the reduction of an aldehyde using sodium borohydride results in the formation of a primary alcohol, with the carbonyl carbon being converted to an alcohol functional group.

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