Sugar Chemistry

[BlackSails]

Advertisement - Members don't see this ad

Is there any good way to remember kilani-fischer synthesis and wohl degradation?

 

[Big Lance]

(sorry, no answer to your question)
but....graduating med school soon(T minus 20 days) and I have no idea what the crap this post is referring too...what is the world coming too????????????????
😕😕

 

[physics junkie]

99% chance this won't show up. The o chem section on the MCAT was cut down to 1 passage with 7 questions on the jan 25th test. Not sure how it was for april.

 

[BerkReviewTeach]

99% chance this won't show up. The o chem section on the MCAT was cut down to 1 passage with 7 questions on the jan 25th test. Not sure how it was for april.

I'll take that bet for Fisher-Kiliani synthesis at 99:1 odds. 🙂

Sure, organic chemistry has been reduced on the MCAT this year (so the SDN feedback makes it seem), but that particular process has bio-applicability and has been tested before. Given that AAMC recycles passages (assuming they choose passages that have well established curves as their comments would indicate), there is a slightly better than 1% chance it will show. Let me have a standing 99:1 bet on every MCAT for the next three years and I'll win at least once in sixty-something MCATs.

 

[unsung]

Is there any good way to remember kilani-fischer synthesis and wohl degradation?

Heh, I just studied this for my final... not that it showed up on the test! I remember Kiliani-Fischer synthesis in 3 steps:

1. nitrile attacks
2. hydrogenate to make imine (w/ poisoned catalyst!)
3. acid hydrolysis of imine gives acid

It's easy to remember that it starts with a nitrile, 'cuz really how many ways of adding a C to an aldehyde do we know? The hard part for me is remembering that a nitrile can be converted to an imine through hydrogenation. And to prevent it going too far, we have to use BaSO4 to poison the H2/Pd combo. Then, imines easily convert to carbonyl groups.

So, that's not really a mnemonic or anything. I don't know what Wohl degradation is... we only learned Ruff degradation.

 

[BlackSails]

Heh, I just studied this for my final... not that it showed up on the test!

It actually did show up on mine. We had to make both D-tetroses from D-glyceraldehyde, and then figure out which stuctue was which sugar.

It's easy to remember that it starts with a nitrile, 'cuz really how many ways of adding a C to an aldehyde do we know?

Grignard, Wittig, Carbon monoxide can probably add to the carbonyl.

I don't know what Wohl degradation is... we only learned Ruff degradation.

They do the same thing. For Wohl, you make an oxime, and then basically do Kiliani Fischer in reverse.