Haworth → Fischer: Back-Convert Ring Sugars to Open-Chain Stereochemistry

Learn how to convert Haworth projections back to Fischer. Identify the anomeric carbon, map up/down substituents, and avoid common sign mistakes.

• Reaction: Cyclic hemiacetal ↔ open chain
• What it does: Recovers the stereochemical pattern in Fischer form
• Typical conditions: Equilibrium via ring opening
• Key intermediate: Open-chain aldehyde/ketone during ring opening
• Driving force: Dynamic equilibrium (mutarotation)
• Exam type: Stereochemistry
• Exam type: Projection conversion