Acetals Flashcards

1
Q

What is the bacterial wall comprised of?

A

The bacterial cell wall is comprised of a cross-linked polymer of alternating Beta (1–> 4)- linked N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)

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2
Q

where is the enzyme lysozyme found and what does it catalyse?

A

Found in tears, saliva, breast milk and mucous

catalyses the hydrolysis of the beta (1 –> 4)- glycosidic linkage

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3
Q

The C=O bond is referred to as the carbonyl group.

What are the 5 basic functional carbonyl groups?

A
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4
Q

Why is the C=O polarised?

A

The oxygen is more electronegative than carbon

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5
Q

What reactions do carbonyl compounds tend to undergo?

Draw the basic example of this reaction

A

Nucleophilic addition

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6
Q

When the carbonyl group is polarised, draw the most stable structure thats produced

A

The +ve carbon is more stable than the +ve OH group

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7
Q

Draw the general structure of acetals

A
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8
Q

Draw the reactions for how acetals can be formed, the products and the catalyst

A

Acetal formation is an acid-catalysed and reversible dehydration

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9
Q

What is the Dean and stark trap used for in acetals ?

A

it is a specialised piece of glassware thats used for continuously removing water formed in a chemical reaction e.g. acetal formation

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10
Q

Complete the following reactions

A
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11
Q

Complete the following reaction

A
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12
Q

The mechanism of acetal formation has how many steps?

A

7 and there is an hemiacetal intermediate

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13
Q

The first part of acetal formation is hemiacetal formation.

What are the first 3 steps of the overall reaction?

A
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14
Q

The second part of acetal formation is forming the acetal from the hemiacetal. What are the 4 steps of this reaction?

A
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15
Q

Protonation serves to ‘activate’ a molecule towards the next step.

Explain how this helps acetal formation and in what steps it occurs

A
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16
Q

Nucleophilic attack takes place upon what ion?

A

An oxonium ion

17
Q

Stability of resonance structures

A
18
Q

How is it known that the final Acetal structure has oxygen from the alcohol present in its structure?

A
19
Q

Are all the steps to the formation of an acetal reversible?

A

yes

20
Q

Complete the reaction

A
21
Q

Complete this reaction

A

Have to protonate to activate the ROR carbon and make the O +ve

22
Q

What is Cellobiose formed from?

How are the monomers linked?

A

It is a dissaccharide formed from two units of beta-D-glucopyranose linked by an acetal which is here termed Beta (1 –> 4) glycosidic linkage

23
Q

Complete the table

A