[sqe]

Hi,

Could someone please provide me some insight as to how to solve the following problems?



1. If histrionicotoxin A (shown above) were treated with pyridinium chlorochromate (PCC) the resulting product would contain the following new functional group:
a. diol
b. alcohol
c. carbonyl
d. alkene
e. amide

Shouldn't the alcohol turn into a ketone? How come ketone is not one of the answers listed?

2. Please see attachment below. I'm not sure where to start and have tried researching this topic on my own already.

Thank you in advance!

[zsinger]

You should show attempts at these problems.  Carbonyl is the correct answer

[zsinger]

Number 2, you need to study carbocation stability , and you shall find guidance.
              -Zack

[sqe]

You should show attempts at these problems.  Carbonyl is the correct answer

For question 1, I learned that PCC oxidizes primary alcohols to aldehydes and secondary alcohols to ketones. How were you able to come to the conclusion that a carbonyl group is produced?

For question 2, for Sn1 reactions, the best carbocation would be tertiary from what I was taught but I'm not too sure if there are exceptions with a benzene ring... I don't think the answer is iv. because allylic carbocation are less stable than tertiary.

Thank you!

[Dan]

For question 1, I learned that PCC oxidizes primary alcohols to aldehydes and secondary alcohols to ketones. How were you able to come to the conclusion that a carbonyl group is produced?

What is the definition of a carbonyl group?

[sqe]

For question 1, I learned that PCC oxidizes primary alcohols to aldehydes and secondary alcohols to ketones. How were you able to come to the conclusion that a carbonyl group is produced?

What is the definition of a carbonyl group?

Jokes... Thanks for pointing out how obvious the answer is..

[zsinger]

Sqe,
Your on the right track with 2, but be sure to be very careful about the meaning of "carbocation stability".  Remember, tertiary carbons are extremely sterically hindered, disallowing a backside attack by even a strong nucleophile in nearly all cases.  Hence, when the LG leaves, the tertiary CC is far more stable than secondary or primary due to induction.  The Carbocation formed in an Sn1 is not extremely picky about the nucleophile it accepts, as it holds a + charge, and wants to get rid of it.  The nucleophile attacks very quickly.  I hope this readers digest version helped.
                     -Zack