8c

Question 1

cyclopropane description

Answer 1

triangle

Question 2

azinide description

Answer 2

triangle with NH as one of the verticles

Question 3

epoxide description

Answer 3

triangle with an O as one of the vertices

Question 4

azetidine description

Answer 4

box with nh as one of the vertices

Question 5

oxetane description

Answer 5

box with o as one of the vertices

Question 6

pyrrolidine description

Answer 6

pentagon with nh as one of the vertices

Question 7

tetrahydrofuran description

Answer 7

pentagon with an o in one of the corners

Question 8

ribose description

Answer 8

pentagon with o as one of the vertices and oh bonded to every other vertice.

Question 9

piperidine description

Answer 9

hexagon with nh as one of the vertices

Question 10

tetrahydropyran description

Answer 10

hexagon with o as one of the vertices

Question 11

dioxane description

Answer 11

hexagon with 2 o’s as vertcies

theyre like on either side of the molecule.

Question 12

piperazine description

Answer 12

hexagon with nh on either side of the molecule.

Question 13

1 bond forming strategy includes the use of what

Answer 13

nucs and electrophiles

Question 14

2 bond forming strategy can occur due to what two things

Answer 14

• en reagents : carbene etc
• enoid : peracid // mcpba

Question 15

whats an ‘en’ reagent

Answer 15

a reagent where the molecule ormally has 2 e- less than the full valence count.

this makes them unstable and hard to make

Question 16

describe a carbene

Answer 16

it has 6 valence e-
its an sp2 hybrid

so all 3 sp2 orbitals are full: meaning theres a lone pair in an sp2 orbital what can be used as a lone pair meaning its nucleophilic.

theres an empty p orbital which is the electrophile as e- can be accepted here.

Question 17

whats cool about the ene reagents

Answer 17

u can form 2 bonds bc theyre nucleophiles and electrophiles at the same time.

Question 18

how do we form a CH2 reagent thats an en reagent meaning its a nuc and electtrophile at the same time

Answer 18

u take NH2CH2 and put energy into it.

this forms CH2

which has an empty p orbital for the electrophile

and a lone pair in the sp2 orbital

Question 19

how does CH2 work as a en reagent : describe the reaction with CH2 and butene

Answer 19

the sp2 lone pair attacks the double bond of the alkene

the double bond of the alkene attacks the empty p orbital on the CH2.

u form a cyclic structure: cyclopropane with methyl substituents

Question 20

whats cool about the en reagent reaction where its a nuc and electrophile at the same time

Answer 20

its a concerted reaction!
means it all happens at once

it also means that stereochemistry remains the same!!

Question 21

along with en reagents,, whats the other reagent that can be used as a nuc and an electrophile and why is this one slightly diff to the ene ones

Answer 21

these are the enoid reagents.

theyre diff as they have a full valence e- count meaning theyre not missing out on any electrons

this makes them more stable + easy to make.

their reactivity is the same as the en specie

Question 22

example of the enoid

Answer 22

mcpba

Question 23

what part of mcpba makes it an enoid

Answer 23

the oxygen of the OH!!
aka the ocygen closest to the end.

bc its got 2 lone pairs

and the mcba bit kinda looks like a carboxylic acid,, which can form a stable ion,, aka a good LG!! so the alkene double bond can attack the O of the OH ,, e- can go into the O-O sigma* antibonding orbital to break that bond and form the anionic carboxylic acid thing.

then this can take the H on the epoxide to form a carboxylic acid and a neutral epoxide

Question 24

C- X where X is a halogen,, what is C

Answer 24

C would be an electrophile as the halogen removes e- density from it

allowing it to accept e- from the nucleophile and kick off the halogen

Question 25

C - MgBr or metal ,, what is C

Answer 25

the C -- metal bond is the nucleophile!! meaning it can ttack things

Question 26

C- X and then u add a metal,, what happens

Answer 26

u get C - Metal - X

Question 27

CH2I2 + Zn describe everything about the product

Answer 27

u have H, H, I, C - Zn - I the C - I bond will be an electrophile the C - Metal - I bon will be the nucleophileee so we have another enoid reagent iggg bc its nucleophilic and electrophilic at the same time. with full valence,, its not missing any e-. if u react it with cyclohexene u get cyclohexane with CH2 in an epoxide type structure, aka the CH2 just kinda sticks out

Question 28

okay describe what 2 reagents are used in a diels alder reaction

Answer 28

- diene - dienophile

Question 29

describe a diene,, the diff ones and what one u need for the diels alder reaction

Answer 29

u need the s- cis diene in the diel alder reaction!!! s for sigma

Question 30

what is the diels alder reaction a type of

Answer 30

its a type of a 2 bond formation reaction

Question 31

what is a dienophile

Answer 31

smt that likes dienes!! its basically an ethene with a methyl ester one the ethene carbons

Question 32

describe the diels alder reaction : the mechanism etc

Answer 32

so u have the diene and the dienophile!! the dienophile attacks the up space between then to form a bond the double bond of the diene is moved to the middle section of the diene the other double bond of the diene attacks the down space between the diene and the dienophile to form another bond u form a cyclic structure with a double bond in it ( the double bond of the diene that moved to the position next to it)

Question 33

whats the driving force of the diel aldes reaction

Answer 33

the driving force is the good orbital overlap between the homo and the lumo of the diene and the dienophile. the orbitals on the end match up to the end orbitals on the other structure, aka theyre both shaded or not allowing constructive overlap !!!

Question 34

how do u figure out the pi stuff for diene

Answer 34

u cout how many pi e- there are aka if u have 2 double bonds u have 4 pi e- so 2 e- levels will be filled with an e- pair. then we draw the energy levels,, so like if have 4 e- levels,, u do 4/2 so u have pi1 and pi 2 and the pi1* and pi2* ,, so u have the bonding and antibonding versionsss so for diene if its butadiene u have 4 pi e-,, so 2 pi level will be filled,, meaning u need the corresponding pi* for each of them!!

Question 35

pi levels for dienophiles

Answer 35

count the number of pi e- if theres 2 pi e- u only need 1 energy level for them to fill up so pi 1 and thn u need the antibonding equivalent,, so pi 1* aswellllll.

Question 36

whats the stereoelectronic effect on ethane,, describe it

Answer 36

any effect on the structure , reactivity or other properties of a molecule that is caused by the spatial position of the molecules orbitals - newman projection etcccc

Question 37

what is the anticonformation in ethane and explain it

Answer 37

sigma CH can interact with the CH sigma** of the other bonds and this interaction is maximised in the anticonformation!! its when theyre staggered kinda!! the bonds are all seen rom the newman projection!!!