[mintyrogue]

I have a question found here, that I'm unable to solve:



For the first step, I think should I hydrogenate the alkene.  Please let me know if this is correct.
However, for the second step, I'm unsure of how to approach it.  Should I deprotect the acetal into a ketone?  If this is correct, how should I do it?

Thank you in advance!

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[Dan]

For the first step, I think should I hydrogenate the alkene.  Please let me know if this is correct.
However, for the second step, I'm unsure of how to approach it.  Should I deprotect the acetal into a ketone?  If this is correct, how should I do it?

These both seem like sensible ideas.

I don't understand the confusion with acetal hydrolysis - you already seem to know the reaction, so I don't understand the reason for the "how should I do it?" question... The usual way - have you looked up the mechanism?

[Pace2014]

Is there any chance the amide could get hydrolysed here? In the likes of likes penicillin, the lactam ring isn't planar, so the nitrogen lone pairs can't conjugate with the carbonyl and there's no double-bond character between the nitrogen and the carbonyl carbon. It's more like an acid anhydride than an amide in terms of reactivity. Not sure what the conformation is in this case, though.

[orgopete]

Is there any chance the amide could get hydrolysed here? In the likes of likes penicillin, the lactam ring isn't planar, so the nitrogen lone pairs can't conjugate with the carbonyl and there's no double-bond character between the nitrogen and the carbonyl carbon. It's more like an acid anhydride than an amide in terms of reactivity. Not sure what the conformation is in this case, though.

I think it would be difficult to "know" this from what is written. If it were a trace of HCl, it would seem less likely. If it were 1.1 equivalents, it would imply formation of a hydrochloride salt. I don't know.

Re: reactivity, I think the nitrogen is not basic as if there were no interaction with the carbonyl group. Beta-lactams have the right reactivity to be acylating agents, yet have reasonable stability in water. I would expect it to hydrolyze simply because it is being treated in an aqueous medium.