GATE CY topic:organic-synthesis PYQs & Answers — Page 3

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Questions 21–30 of 116. Imported answers require independent review unless marked reviewed.

Topic practice 116 questionsPage 3 of 12

In the following reaction, 13.4 grams of aldehyde P gave a diastereomer mixture of alcohols Q and R in a ratio of 2:1.

If the yield of the reaction is 80%, then the amount of Q (in grams) obtained is _____ (in integer).

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The major product in the following reaction sequence is

Your answerChoose one option.

Diagram for Chemistry question 14 (figure 2)

Diagram for Chemistry question 14 (figure 3)

Diagram for Chemistry question 14 (figure 4)

Diagram for Chemistry question 14 (figure 5)

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The major product in the given reaction sequence is Q. The mass spectrum of Q shows ([M] = molecular ion peak)

Your answerChoose one option.

[M], [M+2], [M+4], and [M+6] peaks with relative intensity of 1:1:1:1

[M], [M+2], [M+4], and [M+6] peaks with relative intensity of 1:3:3:1

[M], [M+2], and [M+4] peaks with relative intensity of 1:2:1

[M] and [M+2] peaks with relative intensity of 1:1

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The product M in the following reaction is

Your answerChoose one option.

Structure shown in figure.

Diagram for Chemistry question 17 (figure 2)

Structure shown in figure.

Diagram for Chemistry question 17 (figure 3)

Structure shown in figure.

Diagram for Chemistry question 17 (figure 4)

Structure shown in figure.

Diagram for Chemistry question 17 (figure 5)

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The reaction(s) that yield(s) X as the major product is (are)

X: Ph–CH

–CH

–CO

Your answerSelect all correct options. You can choose more than one.

Diagram for Chemistry question 24 (figure 2)

Ph–CH

–C(=O)–CH

Br; NaOMe

Diagram for Chemistry question 24 (figure 3)

Ph–CH(Br)–C(=O)–CH

; NaOMe

Diagram for Chemistry question 24 (figure 4)

Ph–CH=CH–CO

Me; DIBAL-H (1.0 equiv.), −78 °C

Diagram for Chemistry question 24 (figure 5)

Ph–C≡C–CO

Me; H

, 5% Pd on CaCO

, quinoline

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The reaction(s) that yield(s) 2-methylquinoline as the major product is (are)

Your answerSelect all correct options. You can choose more than one.

o-Aminobenzaldehyde; Me-CHO, aqueous NaOH

Diagram for Chemistry question 25 (figure 2)

Aniline; 1. Me–CH=CH–CHO 2. p-TSA, reflux 3. DDQ

Diagram for Chemistry question 25 (figure 3)

2-Methyl-1H-indole; MeLi, CH

Diagram for Chemistry question 25 (figure 4)

1H-Indole-2,3-dione; 1. NaOH 2. MeCOMe 3. H

, heat

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Consider the following

H-NMR (400 MHz, DMSO-d

) data of a compound:

in ppm: 3.85 (s, 6H), 6.73 (t, J = 2.2 Hz, 1H), 7.1 (d, J = 2.2 Hz, 2H), and 13.05 (brs, 1H).

The compound is

Your answerChoose one option.

Diagram for Chemistry question 40 (figure 2)

Diagram for Chemistry question 40 (figure 3)

Diagram for Chemistry question 40 (figure 4)

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The major products X and Y in the following reaction sequence are

Your answerChoose one option.

Diagram for Chemistry question 42 (figure 2)

Diagram for Chemistry question 42 (figure 3)

Diagram for Chemistry question 42 (figure 4)

Diagram for Chemistry question 42 (figure 5)

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The major products E and F in the following reaction sequence are

Your answerChoose one option.

E and F as shown in figure

Diagram for Chemistry question 43 (figure 2)

E and F as shown in figure

Diagram for Chemistry question 43 (figure 3)

E and F as shown in figure

Diagram for Chemistry question 43 (figure 4)

E and F as shown in figure

Diagram for Chemistry question 43 (figure 5)

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The correct option(s) that give(s) P as the major product (are)

Your answerSelect all correct options. You can choose more than one.

Diagram for Chemistry question 51 (figure 2)

Diagram for Chemistry question 51 (figure 3)

Diagram for Chemistry question 51 (figure 4)

Diagram for Chemistry question 51 (figure 5)

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GATE CY topic:organic-synthesis PYQs

Question 59

Question 14

Question 16

Question 17

Question 24

Question 25

Question 40

Question 42

Question 43

Question 51