Protecting groups

Woopydalan

Hello,

I am unsure of how to utilize protecting groups in organic synthesis problems. What would be an immediate sign to the trained eye that one should use a protecting group such as TBDMS-Cl?

ChiralWaltz

What is the purpose of protecting groups (PG)?

Woopydalan

To protect something from being reduced completely

aroc91

Look for an alcohol that you want to keep in addition to a carbonyl that you want to reduce

ChiralWaltz

• Draw the reagents you can use for protecting different functional groups.
• Notice the similar structures between different reagents used to protect a single functional group.
• Identify the something (functional group) you want to protect.
• Select a reagent you have available for protecting that functional group.
• Push arrows.

Here is wiki's list of functional groups and their protecting groups:
http://en.wikipedia.org/wiki/Protecting_group

When I see TBDMS-Cl, I see a radical Cl anion waiting to react with an acidic hydrogen,usually in a hydroxyl group.