How Does Cyclohexene React with Potassium Permanganate?

TL;DR

Cyclohexene reacts with potassium permanganate under basic conditions to yield a cis-1,2-diol through syn dihydroxylation. The same product is achievable with osmium tetroxide. When a methyl group is present, two distinct diastereomers form, while per iodic acid can convert diols into aldehydes or ketones, depending on their structures.

Transcript

so what's going to happen if we have cyclohexene and if we react it with let's say potassium permanganate kmno4 under basic conditions let's say if we keep the temperature low what's going to be the major product in this reaction under these conditions you're going to get syn dihydroxylation so you're going to get a diol a 1 two dial but with syn a... Read More

Key Insights

• 🕍 Cyclohexene undergoes syn dihydroxylation when reacted with potassium permanganate under basic conditions, resulting in a cis-1,2-diol.
• ❓ The same reaction outcome can be achieved using osmium tetroxide and sodium bisulfite.
• 😋 The presence of a methyl group in the cyclohexene ring leads to the formation of two different stereoisomers of the cis-1,2-diol, classified as diastereomers.
• ❓ Per iodic acid can oxidize diols, converting them into aldehydes or ketones, depending on the presence of additional carbons.
• 🥺 Under acidic conditions, concentrated potassium permanganate cleaves the carbon-carbon bond in cyclohexene, leading to the formation of carboxylic acids or ketones, depending on the carbon's primary or secondary nature.

Summary & Key Takeaways

• Cyclohexene reacts with potassium permanganate under basic conditions, resulting in syn dihydroxylation and the formation of a cis-1,2-diol. The same product can also be obtained using osmium tetroxide and sodium bisulfite.

• The reaction mechanism involves the formation of a manganate ester before hydrolysis to yield the cis-1,2-diol.

• When a methyl group is present in the cyclohexene ring, two different stereoisomers of the cis-1,2-diol are formed, classified as diastereomers.

• Per iodic acid can oxidize diols, converting them into aldehydes or ketones, depending on the presence of additional carbons.