What does cyclic mean? (It means, that some atoms are connected by chemical bonds to at least one chain that has no ends. - GS).

Going off of the previous questions, to be a H bond donor do you need more than one Hydrogen? (One H is sufficient as long as it is acidic enough - GS ) And to be a H bond acceptor do you only need one pair of lone electrons? (Yes, if it is by O, N. or F - GS)

What is the correlation between s character and basicity in amines? (The increased s-character of the orbital holding the electron pair, decreases its energy, and, therefore, decreases basicity. - GS).

How do we determine basicity between different amines? (Conjugation of the electron pair on nitrogen reduces basicity of the amine. - GS).

I know you touched on this at the end of class, but i am still confused. When trying to determine whether or not hydrogen bonds will form between a molecule and water we look for lone pairs, correct?? (Yes. - GS). What about when trying to determine if a molecule will form hydrogen bonds with itself?? (It happens when the molecule contains a both H-bond donor, and a H-bond acceptor. - GS).

What is the difference between alkylation and acylation of amines? Could you please go through an example of each? (Alkylation is introduction of an alkyl group to the amine’s nitrogen. Example - preparation of lecithin from methyl iodide. Acylation is introduction of an acyl group to the amine’s nitrogen. Example - synthesis of acetaminophen from para-aminophenol. - GS).

In Gabriel Synthesis, what deactivates the lone electron pair? (Resonance conjugation with two C=O groups - GS).

Is there a way to predict the major product of an electrophilic substitution reaction for aromatic compounds without doing all of the steps in the reaction mechanism? (Yes. Determine if the existing substituent is ortho-para- or meta-director. - GS).

What is n in 4n+2? I understand that it is an integer but what number does it represent? Principal Quantum number? (No, it comes from the mathematical definition of an odd number of orbitals (2n+1). - GS). It is still not clear. (Each orbitals holds 2 electron, so the number of electrons = 2X(2n+1) - 4n+2. - GS).

Can a substituent be an electron donor and acceptor? (Yes. - GS). If it can, does the electron donor effects always override the acceptor effects? (No. Resonance effects override the inductive effects for activators or deactivators, except for F with its huge inductive effect. - GS).

How do you determine the order of reactivity when comparing cyclodienes, cis-dienes, and trans-dienes? (By their ability to produce the reactive (in the Diels-Alder reaction) s-cis conformation. - GS).

Can you please review how to determine if a compound is aromatic or not depending on the number of conjugated electrons?  I understand how to count the number of conjugated electrons but am unsure of how that relates to aromaticity. Thanks (An aromatic system must contain 4n+2 electrons (n=0,1,2,....) in a cyclic conjugation (uninterrupted by sp3-hybridized atoms. - GS).

Why is having a donor in the Meta position so unfavorable? (Since the sigma-complex has the formal positive charge distributed between ortho- and para-positions, the groups at those positions have the strongest effect on the reaction, so the donor speeds up ortho- and para-substitution much more than meta-substitution. - GS).

How do you identify a “pure acceptor?” How are these different than regular acceptors? (They have no electron-donating effects. - GS).

What does resonance have to do with the weak influence of the donor in the meta position? (Since the sigma-complex has the formal positive charge distributed between ortho- and para-positions, the groups at those positions have the strongest effect on the reaction. - GS).

To clarify- if you have an incoming substituents in the metha or ortho position, there is a strong influence and if you have an incoming substituent in the ortho position there is little influence? (No. Since the sigma-complex has the formal positive charge distributed between ortho- and para-positions, the groups at those positions have the strongest effect on the reaction.The incoming substituent has almost no influence, because it attaches to an sp3-carbon with no formal charge - GS).

How do you determine whether a compound will go through the SN1 reactions slower or faster?? (More stable intermediate carbocation, higher concentration of the substrate, and a better leaving group will all make the reaction faster. - GS).

Just to clarify something with more substituents is more stable than something with less? (That is true for C=C bonds and carbocations. There are other examples. - GS).

So far we learned about ortho and para positions but do compounds ever go to the meta position and if so when does that happen? (Electrophiles always enter the meta-position,, but preferably - when the existing group has no donating effects. - GS). Also can you go over why meta isn’t as favorable as ortho or para please, I’m still confused why it isn’t? (The sigma-complex has the positive charge distributed over the ortho- and para-positions, so it is stabilized better by ortho- and para- electron-donating substituents, which makes the ortho- and para-orientation preferred. Ortho- and para-substituents with no electron-donating effects are are having trouble withdrawing electrons from the positively-charged ortho- and para-positions, which makes ortho- and para-orientation unfavorable, so the meta-substitution is preferred. - GS).  

How do you tell if something has a resonance electron withdrawing effect? (There is a X=O bond or empty d-orbital (like in Cl, Br, and I) in conjugation with the benzene ring - GS).

Can you go over another example of the pi-complex and sigma-complex mechanisms? I don’t really know the distinction between the two quite yet. Thanks!! (They are steps of the same mechanism of aromatic electrophilic substitution: http://ochem.orgfree.com/SEAr.html  - GS).

How do we know if lone pairs participate in regards to aromatic and antiaromatic compounds? (It participates if it can be perpendicular to the plane of the ring and, therefore, align with the pi-system. It will always happen if that space is not already occupied by a p-orbital of the pi-system. - GS).

How do we know if a carbon is allylic? (If it is next to C=C, which is not a part of an aromatic ring. If it is, the carbon is benzylic. - GS).

For clarification does the acidity dictate the aromaticity of the molecule? (No. - GS). Is a more acidic compound automatically aromatic if it follow Huckel’s rules? (No. Aromaticity increases stability of the conjugate base, which increases acidity of the conjugate acid - GS).

So when a molecule is twisted it can not be either aromatic or anti-aromatic?(Correct - GS). No matter the number of electrons? (Correct - GS) Would a non-aromatic molecule be more stable than an anti-aromatic molecule? (Correct - GS)

I understand that hydroboration followed by oxidation is used when we need to perform hydration of a double bond against markovnikov’s rule, however, at what point is the markovnikov’s rule broken? According to markovnikov, the halogen of the hydrogen halide attaches to the carbon of alkene bearing the fewer number of hydrogen and greater number of carbons, so does this mean the rule is broken when the conditions are changed as to where it attaches? (That was the original rule formulation of Markovnikov’s himself. Now, we understand the rule broader: instead of halogen, it can be any negative part of the reagent. The rule usually works if addition proceeds through a carbocation, which is not the case for hydroboration. - GS).

Does the SP3 bond break when its fragments are rotated? (There are no sp3 bonds. - GS). Also, can you please give an explanation on this concept. Thanks!  (Sigma-bonds do not break, because the bond-forming orbitals (may involve sp3-orbitals), overlap in only one area. Pi-bonds break, because the bond-forming p-orbitals overlap in two areas, which have to disconnect during the rotation.. - GS).

When selecting R or S configuration, I know that we 1. Rank substituents by highest priority (highest atomic mass) 2. Find out which way priority is decreasing 3. If priority is decreasing clockwise, then R configuration… If priority is decreasing counterclockwise, then S configuration 4. Change R configuration to S configuration, or vice-versa, if lowest priority group is pointing to the front….. I understand all of this, however, I always get confused when the lowest priority group is neither pointing towards you or away from you…. Do we still flip the configuration if the lowest priority group is in the plane of the paper? (Flip the lowest in priority group, which is in the plane of paper with the group behind paper, determine configuration as usual, and flip your answer. - GS).   Or do we instead have to rotate the molecule in our minds in order to get the lowest priority facing away, and then go ahead and figure out the configuration?  Spasibo.  (This will also work.  Choose either method, depending on your individual strengths. - GS).  Your advice to flip the lowest priority, which is in the plane of paper, with the group behind the paper, determine configuration, and flip the answer sounds much better.  That really cleared things up.  Thank you!!

Are all H atoms abstracted from beta carbons only? (No. It is true for E1 and E2 reactions - GS). What other conditions are necessary for H abstraction? (Besides of E1 and E2, it is also free radical abstraction, and some other reaction conditions outside of the scope of this course. - GS).

Actually, please explain the entire concept of Solvent Effects on Nucleophilicity. Please be specific on what we need to know. Thanks. (As opposed to protic solvents, aprotic solvents selectively solvate cations, leaving anions “untamed”. This reverses the nucleophilicity trend of anions in groups, such is from F to I - GS).

Please explain further what polar aprotic solvents are? (There are polar solvents with no protons acidic enough to create hydrogen bonds - GS).

Are nonpolar solvents aprotic? (Yes. - GS). What is the connection if there is any? (Protons acidic enough for hydrogen bonds, create polarity, but there are other sources of polarity - GS).

Please explain why diluting a system of Sn1 and Sn2 will favor Sn1 and why concentrating the same system will favor Sn2. (Because the reaction rate of SN1 is proportional to the total concentration, while the reaction rate of SN2 is proportional to the square of the total concentration. - GS).

Can you explain how you know which reaction will be more efficient in an E2 reaction? (Usually by Zaitsev rule in the anti-fashion, unless the alternative regio- and stereo-pathways have lower transition states. - GS).

Why are some bonds only partially formed? (Because it corresponds to the lowest energy of the system when the atomic nuclei are in the process of moving from one intermediate to the next one on the reaction pathway. - GS).

Is it true for majority of reactions that you can’t obstruct a Hydrogen from an alpha Carbon and it has to be beta? (Yes, beta-abstraction is preferred over alpha-abstraction - GS).