[janapix]

I'm working on the mechanism of a multi-step synthesis and am having trouble with how this proceeds:

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/q1.png

Where/how does initial attack occur?
NO₂ gas is lost so I assume this proceeds through a nitrate ester.

Could someone please help me with this?

[discodermolide]

I'm working on the mechanism of a multi-step synthesis and am having trouble with how this proceeds:

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/q1.png

Where/how does initial attack occur?
NO₂ gas is lost so I assume this proceeds through a nitrate ester.

Could someone please help me with this?

Presumably you get the nitrite ester as you said, R₂HC-ONO₂ this will eliminate NO₂ by abstraction of the proton of the nitrite ester with formation of the ketone.

[Schrödinger]

^Pretty much the same mechanism as chromic acid. Chromate ester is formed, and the Chromate part is eliminated by the abstraction of a proton.

[janapix]

Thank you both. I believe I've got it now:

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/University%20stuff/q2.png

[discodermolide]

Thank you both. I believe I've got it now:

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/University%20stuff/q2.png

Not quite the last step is removal of the proton next to the nitrate ester with elimination of NO2 and formation of the ketone.
A N-O bond containing a positive N atom cannot loose a further two electrons.

[orgopete]

Thank you both. I believe I've got it now:

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/University%20stuff/q2.png

You have five bonds to the carbon. The CH is still present from the curved arrows.

[janapix]

Cheers... that was pretty thick of me to not notice the valency of N or C...
Hopefully THIS one is right =)

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/University%20stuff/q2-1.png

[discodermolide]

Cheers... that was pretty thick of me to not notice the valency of N or C...
Hopefully THIS one is right =)

image link: http://i317.photobucket.com/albums/mm395/MunsterMunster/University%20stuff/q2-1.png

This looks better now.

[janapix]

=D excellent. Thanks.

[orgopete]

The acetate ion concentration is probably zero in nitric acid. Water is the most likely base present.