Asked Mar 4, 2020

Draw a stepwise mechanism for the following reaction.

(2 equiv)

Image Transcriptionclose

ОН Н (2 equiv) H* HO.. ОН НО НО Он


Expert Answer

Step 1

To form the target molecule, the conversion of pyranose into furanose takes place. The mechanism of the reaction is preceded by the protonation of the starting material, followed by shifting of electrons present on hydroxyl group to stabilize oxonium ion. In the next step, a hydroxyl group attached to fourth carbon attacks on the first carbon atom to generate furanose ring with a positive charge on -O atom followed by reaction with A- base to form furanose ring. The stepwise mechanism for the conversion of pyranose into furanose is shown below:

Chemistry homework question answer, step 1, image 1

Step 2

The [1] step of the reaction comprises the protonation of the carbonyl compound to produce alcohol. The hydroxyl group is attached to the electron deficient carbon atom. The corresponding reaction is shown below:

Chemistry homework question answer, step 2, image 1

Step 3

In [2] step, the electrons present on -OH group of furanose attacks on electron-deficient carbon atom of an alcohol, followed by [3] step in which abstraction of H+ ion by water takes place to form a hemiacetal. The corresponding reactions are shown b...

Want to see the full answer?

See Solution

Check out a sample Q&A here.

Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.

Related Chemistry Q&A

Find answers to questions asked by student like you
Show more Q&A

Q: A mixture is prepared by combining 11.34 mL of 2.36 x 103 M Fe(NO3)3 with 10.00 mL of 1.66 x 10-3 M ...

A: Click to see the answer


Q: What is the order with respect to A for this reaction givven the experimental data below? Concentrat...

A: Given, 4A (g) + 3B (g) → 2C (g)   The rate law for this reaction will be:


Q: Compare the following ionic compounds and determine which bond is stronger and why? A. LiCl or NaCl ...

A: As per guidelines, we only answer up to 3 sub-parts, we’ll answer the first 3. Please resubmit the q...


Q: What products are formed when each compound is subjected to a Kiliani–Fischer synthesis?

A: The steps involved in Kiliani—Fischer synthesis of D-lyxose follows:Step-I Reaction of given aldose ...


Q: What alkene is needed to synthesize each amino acid by an enantioselective hydrogenation reaction us...

A: The amino acid, alanine is formed by enantioselective hydrogenation of achiral alkene with hydrogen ...


Q: (a) Draw the more stable chair form of fucose, an essential monosaccharide needed in the diet and a ...

A: The Fisher projection is drawn by converting the stable staggered conformation into less stable ecli...


Q: Sulfuric acid reacts with ammonium hydroxide.  What is the sum of the coefficients for the reactants...

A: Sulfuric acid (H2SO4) on reaction with ammonium hydroxide (NH4OH) gives ammonium sulfate ((NH4)2SO4)...


Q: compo 2. Which will react the fastest in the electrophilic addition reaction? hree or feyver car (c)...

A: In electrophilic addition of a Bronsted acid (hydrogen halide) to an alkene, the reaction takes plac...


Q: What α-halo carbonyl compound is needed to synthesize each amino acid: (a) glycine; (b) isoleucine; ...

A: (a)The alpha-halo carbonyl compound needed to synthesize glycine must have same number of carbon ato...