Rules of the Day
Click here for a copy of my lecture notes from today's lecture
Click here for the other handouts used in class today
SPECIAL PRICING FOR UT: $30 to register for 5k = clean water for 1 person. ? Discount code: R4TW25HOOKEM
When registering for 5k: join Dr. Iverson’s team: OChem Iverson
Here is Team Ochem Iverson's unique registration link: https://raceroster.com/events/2025/102453/run-for-the-water/register?team=871280 And if you won’t be running but would like to support Gibert and the Gazelle Foundation, you can volunteer at the packet pickup before the race, or during the race you can work at a water stop (water stops 3,4,5 and 6 are going to be staffed by UT students like you!) where you provide water for the runners. You can get to the volunteer sign up by clcking here: https://raceroster.com/events/2025/102453/run-for-the- water/volunteer?_gl=1*vluhd*_gcl_au*MTczMzQ3MDU3Ni4xNzU5NzA3Mzk2*_ga*MTc 3NDA1NjI3Ny4xNzU5NzA3Mzk2*_ga_XSJQX37G0F*czE3NTk5Mzk3ODUkbzQkZzEkd DE3NTk5NDAyMjckajQzJGwwJGgw From the Gazelle Foundation: “Water stops 3, 4, 5 and 6 are labeled "UT only". If students are more interested in packet pickup and we don't get quite enough to fill those spots, no worries. We'll supplement with other interested volunteers. Just wanted to make sure your students get first dibs and the chance to be with each other1.There are four different mechanisms possible when a haloalkane reacts with a nucleophile/base. It is important to categorize the nucleophile/base with respect to nucleophile and base strength. Click here for a table of nucleophiles grouped by nucleophile and base strength and a mechanism decision map.
A) SN2 (Substitution, Nucleophilic, Bimolecular) - reaction involves a single step in which nucleophile attacks backside of a carbon-leaving group bond (the electrophile), making a new bond as the leaving group departs. Click here to see a movie of an SN2 reaction. There is an InVERSiON of stereochemistry at the site of an SN2 reaction.
B) E2 (Elimination, Bimolecular) - anti-periplanar - involves a base reacting with the proton that MUST be anti-periplanar to the leaving group (that simultaneously leaves) in a single step to give an alkene. Click here to see the movie.When there is a choice in an E2 reaction, the more stable alkene predominates. This is referred to as Zaitsev's rule.
C) When a weak nucleophile/very weak base is used with a tertiary haloalkane, upon heating, not much happens until a carbocation is produced by spontaneous departure of the halide (slow). The cation then reacts through a combination of SN1 (Substitution, Nucleophilic, Unimolecular) and E1 (Elimination, Unimolecular) pathways in which a nucleophile is added or a proton removed from the carbocation, respectively.
2. It is important to categorize the nucleophile/base with respect to nucleophile and base strength. Click here for a table of nucleophiles grouped by nucleophile and base strength and a mechanism decision map.
3. For highly substituted haloalkanes you must look for the correct conformation in which the H and X are antiperiplanar in order to identify whether the product alkene is E or Z.A) Methyl and primary haloalkanes react with the SN2 mechasnism for all nucleophiles in the table except for tBuOK. tBuOK is a srong base that is so stereically hindered it cannot undergo an SN2 reaction, so even primary haloalkanes will undergo an E2 reaction with tBuOK.
B). For secondary haloalkanes, the strong bases labeled in the table react predominantly via the E2 mechanism. Most other nucleophiles react via the SN2 mechanism, except for the "very weak bases" listed in the table that react via the SN1/E1 pathway.
C). Tertiary haloalkanes react via E2 (never SN2) except when the "very weak bases" listed in the table are used, then they go SN1/E1.
HOMEWORK:
Read: Sections 9.5 - 9.9.
Take the Daily Quiz 18 before 10 PM tomorrow. Click here to access the quiz. These quizzes are designed to review the important material from today's lecture.
Finish Working on Homework Problem Set 8, due at 10 PM on Wednesday, November 5.
Click here to get a copy of the Gradescope Homework Problem Set 8
There is no Aktive learning homework due on November 5th.The Gradescope homework is challenging and I would like you to focus on it.
Start Working on Homework Problem Set 9, due at 10 PM today, November 12.
Click here to go to the Aktive Homework Problem Set 9
Click here to get a copy of the Gradescope Homework Problem Set 9