Preparation of Alcohol - Hydroboration-Oxidation

$$\text{R--CH=CH}_2 \xrightarrow{1) \; \text{B}_2\text{H}_6 / \text{THF} \quad 2) \; \text{H}_2\text{O}_2 / \text{OH}^-} \text{R--CH}_2\text{--CH}_2\text{OH}$$

Concept: A two-step synthetic pathway involving concerted addition of diborane ($$\text{B}_2\text{H}_6$$ or $$\text{BH}_3 \cdot \text{THF}$$) across the double bond, followed by alkaline peroxide oxidation to replace the boron group with a hydroxyl group.

Notation & Key Points:

• Regioselectivity: Yields net Anti-Markovnikov addition ($$\text{--OH}$$ group bonds to the less substituted carbon atom).
• Stereochemistry: Proceeds via Syn-addition (both $$\text{--H}$$ and $$\text{--OH}$$ are added to the same face of the alkene).
• Rearrangements: Concerted four-center cyclic transition state ensures no rearrangements occur.