Chapter 11 - Alkynes

studied byStudied by 0 people
0.0(0)
learn
LearnA personalized and smart learning plan
exam
Practice TestTake a test on your terms and definitions
spaced repetition
Spaced RepetitionScientifically backed study method
heart puzzle
Matching GameHow quick can you match all your cards?
flashcards
FlashcardsStudy terms and definitions

1 / 14

encourage image

There's no tags or description

Looks like no one added any tags here yet for you.

15 Terms

1

Alkynes

Triple Bond, Terminal Alkynes, Internal Alkynes

New cards
2

Nomenclature

Suffix: "-yne"

• Find longest chain containing both carbons of the alkyne

• Number giving alkyne the lowest number

• Multiple Alkynes: -diyne (2), -triyne (3)

• Molecule with both Alkene and Alkyne Bonds: -enyne

The chain gets numbered to give the first point of

unsaturation at the lowest number

• Alkyne + Alcohol: -ynol (numbered with alcohol at lowest

number)

• Common Name: for ethyne (2 carbon alkyne) - acetylene

• As a substituent: ethynyl

New cards
3

Preparation

E2 reactions of geminal or vicinal dihalides

• Reagents - 2 possibilities

• NaNH2 (sodium amide - 2 equivalents)

• KOtBu (2 equivalents), DMSO, H2O

New cards
4

Hydrohalogenation

2 equivalents of H-X added

• Both hydrogens added to same carbon atom

• Markovnikov Addition seen with terminal alkynes

• Best for symmetrical or terminal alkynes - other wise see 2

products (constitutional/regio isomers)

• 1 equivalent of H-X will stop reaction at the alkene

New cards
5

Halogenation

• Addition of 2 equivalents of X2

New cards
6

Hydroboration-Oxidation

Terminal Alkyne: BH2 ends up on least substituted carbon

leading to an aldehyde product after oxidation

• Ketone/Aldehyde products form from tautomerization of enol

• Comparison with Hydration conditions with acid/Hg2+

• No difference for internal alkynes

• Terminal alkynes acidic conditions give ketone,

hydroboration conditions give aldehyde

New cards
7

Reactions of Acetylide Ions

Substitution/Elimination Reactions with Alkyl Halides

• Ring opening of epoxides (as strong nucleophiles)

New cards
8

Synthesis

• Retrosynthetic Analysis: planning a synthesis of a compound

involving more than one step - working backwards from

product to starting material

New cards
9

Hydrohalogenation 2

Add 2 equivalent of H-X to get geminal dihalide

New cards
10

Halogenation 2

Add 2 equivalent of X-X to get tetrahalide (anti addition of X2)

New cards
11

Hydration 2

Add H2O, H2SO3, HgSO4 gives ketone (enol intermediate)

New cards
12

Hydroboration-Oxidation2

1. R2BH, 2.H2O2 HO gives aldehyde (enol inteermediate)

New cards
13

Formation of acetylide anions

terminal alkyne + strong base (NaH or NaNH2) give acetylide anions

New cards
14

Acetylide anions react with electrophiles

Sn2

New cards
15

Acetylide anions and epoxides

Acetylide anions and epoxides in water make H-C(TB)C-CH2CH2OH

New cards

Explore top notes

note Note
studied byStudied by 18 people
899 days ago
5.0(1)
note Note
studied byStudied by 32 people
794 days ago
5.0(1)
note Note
studied byStudied by 1 person
28 days ago
5.0(1)
note Note
studied byStudied by 103 people
856 days ago
5.0(1)
note Note
studied byStudied by 3 people
761 days ago
5.0(1)
note Note
studied byStudied by 10 people
693 days ago
4.5(2)
note Note
studied byStudied by 39 people
953 days ago
5.0(1)
note Note
studied byStudied by 11 people
776 days ago
5.0(1)

Explore top flashcards

flashcards Flashcard (33)
studied byStudied by 3 people
792 days ago
5.0(1)
flashcards Flashcard (62)
studied byStudied by 5 people
765 days ago
5.0(1)
flashcards Flashcard (82)
studied byStudied by 10 people
56 days ago
5.0(1)
flashcards Flashcard (40)
studied byStudied by 5 people
171 days ago
5.0(1)
flashcards Flashcard (20)
studied byStudied by 115 people
507 days ago
5.0(1)
flashcards Flashcard (25)
studied byStudied by 12 people
468 days ago
5.0(1)
flashcards Flashcard (25)
studied byStudied by 2 people
661 days ago
5.0(1)
flashcards Flashcard (38)
studied byStudied by 38 people
8 days ago
5.0(1)
robot