With an abrupt start to my day (i.e. sleeping at 6:30 am and waking up at 3:30 pm), I'm finally here at the library, about to begin my 8-hour descent into the world of chemistry.
I reckon I'll be updating this post as the day goes on if I have anything I want to provide you guys with. However, I do have some words of wisdom:
1. Avoid "mental fixedness"
I struggle with this problem, every. single. time. As soon as I can see a way to solve a problem, my brain literally "locks in" and I run like a horse towards that solution. I lose sight of other ways I could have solved the problem, and sometimes that comes back to bite me in the ass. If you see my exams or midterms, you'll notice that some of my answers are completely different from the topic that the question is about, but they still work. I just see my own solution and snipe it. It's good to be able to see solutions in questions, but I advise you do take a second to "step back" and assess your solution and probe for other possible solutions. Even today this day, I'll check the solutions manual and I'll get slapped in the face with a much more elegant solution and I'm like "Damn! What was I thinking?". This leads me to piece of advice #2:
2. Read the questions.
Legit. You can really help yourself out by reading the question topic. If it says "Substitution at Carbonyl with a loss of Oxygen",then you KNOW what kind of mechanisms and products to expect. Use the question titles as tools... they're the railings along the sides of each lane when you go bowling. They're there so you don't run off a cliff.
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Last night, after submitting a 17-page report, I wrote down a list of gaps in my understanding. Today I plan on putting on my plumber outfit and sealing those cracks. Then, I'm going to go through the midterms - re-correct my mistakes so they don't happen again. I have to get on the ball with Schotten Bauman. I have to teach myself Birch reductions. I'm going to try out Patrick Gunning's examination from last year using the library's website. Then, I'm going to tackle the last few practice questions posted by Dr. Leigh on blackboard. Possibly also redo some synthesis questions from WASPS. Then, I'm going to quickly go over the slides from each week and make sure I'm on the ball with every slide. Long day ahead.
Chao!
Stay tuned.
Today's Tune: West Coast Gangsta Rap Instrumental
6:30 pm: Just finished Gunning's final from last year. It was pretty straightforward, I'd recommend trying it out for practice. You can find it on the library's website. I added two more reagents to my arsenal:
NBS & dil. acid: Used to brominate allylic carbons - we covered this in CHM242.
OsO4 & pyridine: Used to make syn-diols from an alkene.
10:30 pm: Up to this point, I've taught myself how to make Wittig reagents, I've learned how to turn a ketone into an ester using mCPBA, I've re-learned the reagents required to put alcohols on Anti-Markonikov, I've learned how to perform a Birch reduction, and I was slapped in the face with an abrupt reminder that organolithiums and grignards will react with carboxylic acid derivates twice to form tertiary alcohols just because of how reactive they are as nucleophiles. As it turns out, to get a single addition-substitution - you should use organocuprates or perhaps a Weinreib amide, or convert the group to a carboxylic acid and use two equivalents of organolithiums and work it up.. the list is endless it seems. I've also learned the Luche reduction (NaBH4 with CeCl3) to selectively reduce a C=O bond in the presence of a C=C bond, as is in an enone.
Now, I'm going to practice some Birch reduction questions, read up on Benzyne chemistry, finish up some more of Leigh's practice problem sets, and then maybe also do a problem set for grignard's, organolithiums and the like.
5:00 am: Slept.
6:30 pm: Just finished Gunning's final from last year. It was pretty straightforward, I'd recommend trying it out for practice. You can find it on the library's website. I added two more reagents to my arsenal:
NBS & dil. acid: Used to brominate allylic carbons - we covered this in CHM242.
OsO4 & pyridine: Used to make syn-diols from an alkene.
10:30 pm: Up to this point, I've taught myself how to make Wittig reagents, I've learned how to turn a ketone into an ester using mCPBA, I've re-learned the reagents required to put alcohols on Anti-Markonikov, I've learned how to perform a Birch reduction, and I was slapped in the face with an abrupt reminder that organolithiums and grignards will react with carboxylic acid derivates twice to form tertiary alcohols just because of how reactive they are as nucleophiles. As it turns out, to get a single addition-substitution - you should use organocuprates or perhaps a Weinreib amide, or convert the group to a carboxylic acid and use two equivalents of organolithiums and work it up.. the list is endless it seems. I've also learned the Luche reduction (NaBH4 with CeCl3) to selectively reduce a C=O bond in the presence of a C=C bond, as is in an enone.
Now, I'm going to practice some Birch reduction questions, read up on Benzyne chemistry, finish up some more of Leigh's practice problem sets, and then maybe also do a problem set for grignard's, organolithiums and the like.
5:00 am: Slept.
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