Ch 10 Alcohols

Question 1

synthesis gas

Answer 1

CO₂ + 2 CO + 4 H₂

Question 2

Answer 2

Nucleophilic Substitution on an Alkyl Halide

Usually via the SN2 mechanism; competes with elimination. Inversion of stereochemistry.

Question 3

Grignard reagent

Answer 3

The organomagnesium halides, of empirical formula R - Mg - X

Question 4

Answer 4

synthesis of a Grignard reagent

Question 5

Answer 5

synthesis of a Grignard reagent

Question 6

Answer 6

synthesis of a Grignard reagent

Question 7

what kind of solvent is required to synthasise a Grignard reagent?

Answer 7

a solvent containing the ether funtional group

Question 8

THF

Answer 8

Question 9

describe the formation of the Grignard reagent

Answer 9

Grignard and organolithium reagents provide some of the best methods for assembling a carbon skeleton. These strong nucleophiles add to ketones and aldehydes to give alkoxide ions, which are protonated to give alcohols.

Formation of the Grignard reagent: Magnesium reacts with an alkyl halide in an anhydrous ether solution.

Question 10

Explain the first step in carbon skeleton formation using a pre-made Grignard or organolithium reagent

Answer 10

Reaction 1: The Grignard reagent attacks a carbonyl compound to form an alkoxide salt.

Question 11

Explain the second step in carbon skeleton formation using a pre-made Grignard or organolithium reagent

Answer 11

Reaction 2: After the first reaction is complete, water or dilute acid is added to protonate the alkoxide and give the alcohol.

Question 12

How would you form a primary alcohol?

Answer 12

Addition of a Grignard reagent to formaldehyde

Question 13

Answer 13

Acid-catalysed hydration. Markovnikov orientation, syn addition.

Question 14

convert alkene to epoxide (diol), syn addition

Answer 14

Syn Dihydroxylation.

Osmium tetroxide (OsO₄) and peroxides (H₂O₂)

-or-

Potassium permanganate (KMnO₄) and hydroxide ion (^-OH) (cold, dilute)

Question 15

Convert an alkene to an alcohol with Markovnikov orientation.

Answer 15

Acid-catalysed hydration.

Question 16

convert an alkene to an alcohol with Markovnikov orientation, anti addition.

Answer 16

Oxymercuration–demercuration. Hg(OAc)₂ + H₂O.

Question 17

convert an alkene to an alcohol, anti-Markovnikov orientation, syn addition.

Answer 17

Hydroboration–oxidation with peroxides.

(1) BH₃ •THF, (2) H₂O₂, NaOH

Question 18

convert alkene to epoxide (diol), anti addition

Answer 18

Anti Dihydroxylation. peroxy acid (HCO₃H) and hydronium (H₃O⁺)

Question 19

convert grignard into a secondary alcohol with one additional carbon

Answer 19

Addition of a Grignard or organolithium reagent to an aldehyde.

(1) ether, (2) hydronium (H3O+)

Question 20

convert grignard into a primary alcohol with one additional carbon

Answer 20

Addition of a Grignard or organolithium reagent to formaldehyde.

(1) ether, (2) hydronium (H₃O⁺)

Question 21

convert grignard into a tertiary alcohol with one additional carbon, with one of the final three R groups derived from the grignard reagent.

Answer 21

Addition of a Grignard or organolithium reagent to a ketone.

(1) ether, (2) hydronium (H3O+)

Question 22

convert grignard into a tertiary alcohol with one additional carbon, with two of the final three R groups derived from the grignard reagent.

Answer 22

Addition of a Grignard or organolithium reagent to an ester or acid halide (Cl shown).

(1) ether, (2) hydronium (H3O+)

Question 23

aldehyde to alcohol with no extra carbons added

Answer 23

NaBH₄ (mild sauce)

or

LiAlH₄ (hot sauce)

Question 24

ketone to alcohol with no extra carbons added

Answer 24

NaBH₄ (mild sauce)

or

LiAlH₄ (hot sauce)

Question 25

convert grignard into a primary alcohol with two additional carbons

Answer 25

**Addition of a Grignard or organolithium reagent to ethylene oxide (an epoxide).** (1) ether, (2) hydronium (H3O+)

Question 26

carboxcylic acid anion in base to alcohol with no extra carbons added

Answer 26

LiAlH₄ (hot sauce) **ONLY** NaBH₄ (mild sauce) **NO RXN!**

Question 27

ester to alcohol with no extra carbons added

Answer 27

LiAlH₄ (hot sauce) **ONLY** NaBH₄ (mild sauce) **NO** **RXN!**

Question 28

Answer 28

**Raney Nickel** works like hot sauce (LiAlH₄), but also hydrates and reduces carbon double bonds (C=C), making the product an alkane alcohol