Stuff I messed up on - OCHEM prep 2

DeltaH equation

Yes—a negative ΔH means the reaction releases heat to its surroundings. That’s an exothermic reaction.

delta G equation

IT’S NEGATIVE

WHAT ARE TRANSITIONS STATES? WHY ARE THEY ALWAYS HIGHER IN ENERGY

D. Why is the transition state higher in energy? A transition state is the highest-energy arrangement along a reaction step. Existing bonds are distorted and partly broken, while new bonds are not yet fully formed. This loses stabilizing bonding interactions. Developing charge, electron-cloud repulsion, and distortion of bond angles or lengths can also raise its energy. It is a barrier, not a stable intermediate.

what are all the general reaction names and simple definitions?

Front: What are the general reaction types?

Back:

• Addition: Adds atoms or groups across a double or triple bond, decreasing the number of π bonds.

• Elimination: Removes atoms or groups, usually forming a double or triple bond.

• Substitution: Replaces one atom or group with another.

• Rearrangement: Moves atoms or groups within a molecule, changing its connectivity.

• Oxidation: Loss of electrons; in organic molecules, usually more bonds to O, N, or halogens, or fewer bonds to H.

• Reduction: Gain of electrons; in organic molecules, usually more bonds to H, or fewer bonds to O, N, or halogens.

• Acid–base / proton transfer: Transfers an H⁺ from an acid to a base.

what type of reaction is this?

SUBSTITITUION, the CO bond is substituted with something else!

what type of reactio is this?

PROTON TRANSFER

If a stereocenter doesn’t have a wedge…

WE CAN”T CLASSIFY IT AS S OR R

What does E/Z mean in context of naming things? WHEN DO YOU NEED TO INCLUDE IT?

You include E/Z when a double bond can have two different geometric arrangements and the drawing specifies which one it is.

PRETTY MUCH EVERYTIME THERE IS A DOUBLE BOND SILLY BILLY!!

When you’re doing r vs s…

REMEMBER THAT THE 4 one (least impactufl) GOES AWAY FROM YOU

what is a racemic mixture?

1:1 mixture of enantiomers

Deciding carbon one around a ring deciding order of things in name

ALWAYS MAKE LOWEST NUMBERS POSSIBLE BUITTTTT

DON’T FORGET TO PUT THINGS ALPHABETICALLY EVEN IF IT”S OUT OF NUMBER ORDER.

what does trans mean in terms of stuff?

what is it called when a group is removed?

ELIMINATION, NOT SUBTRACTION silly

how do you calculate DeltaH using bond energies?

Bonds broken - bonds formed = DeltaH

Negative means that energy was released

what is negative DeltaS?

LESS ENTROPY

Negative DeltaH?

Exothermic reaction

WHAT GOES IN THE BACK???

the weakest gorup

How does Tri/di stuff affect ordering for names?

It doesn’t!

ignore it and only account for the actual prefix

If you have an extra group attached through the main guy, where do you put it in?

in the very front!!!!, even before the 2R and E stuff

why is this naming so stupid

Because you ignore “tert-” when alphabetizing:

• tert-butyl → alphabetize under b for butyl.

• 3-chlorophenyl → ignore the number and alphabetize under c for chlorophenyl.

B comes before C, so tert-butyl comes first.

When you are labeling the affect of groups…

BE CAREFUL BRO AND GO THROUGH SLOWLY

what do the + and - mean when doing ee stuff?

the plus means that light is getting rotated clockwise

the negative means that light is getting rotated counterclockwise

Understand what the rate constant means

Reaction rate depends on how often the necessary reactants reach the transition state.
A larger transition-state barrier means a smaller rate constant \(k\), and therefore a slower reaction.

When you are ordering the power of different groups for R vs S stuff, what wins, C-Cl or C-C3? C-N vs C-C3?

C-Cl and C-N win because cl and N have higher atomic numbers than C, DON’T add up the atomic numbers of C! It’s just whatever is higher.