O-CHem questions pleaaaaseeee help

[navneetdh]

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1. Quinoline or Lindlar's catalyst is a poison which stops reduction of alkynes at alkene stage. So H2, Pd/BaSO4 takes to alkene. But I also read that 2H2/Pt will take to alkane stage. So will H2 Pd/BaSO4 also take it to alkane stage if Quinoline wasnt present??? Is it just Quinoline that stops it?

2. would terminal alkynes in hot basic KMnO4 also give off CO2 like terminal alkenes do?

3. Does sulfonation of Benzene need heat? Because I know reverse of Sulfonation happens only if heat is provided.

4. LiAlH4 is the strongest reducing agent out there and reduces COOH and esters(RCOOR), but not ethers. WHat reduces ethers??? CAn they even be reduced??

5. In Williamson ether synthesis you make ethers from reaction of "metal alkoxides" from Primary alkyl halides or tosylates. But How do you make metal alkoxides??



I hope my questions are understandable. Sorry I couldn't illustrate with structures, I dunno how to show them here.

ANy help is awesome!! 😀

 

[loveoforganic]

1. You'd get reduction to alkane. Lindlar's catalyst you can think of as poisoned palladium - it's less effective than pure palladium and only reduces to the alkene.

2. I believe so.

3. Dunno. That's rather specific.

4. The only reactivity that straight chain ethers and cyclic ethers without ring strain undergo is with concentrated acid (cleavage).

5. Metal alkoxides are typically synthesized in a radical mechanism by addition of lithium, potassium, or sodium metal to an alcohol. Actually, I think the williamson ether synthesis might specifically use sodium hydride to form metal alkoxides. Sodium hydride is just a very strong base that, when protonated, bubbles out of the solution as H2, leaving sodium as the counterion.

 

[navneetdh]

Thank You

That helps a lot!!