[pfnm]

"Reaction of compound A with sodium amide and ammonia followed by bromomethane yielded compound B.

Compound C is produced when B is isolated and treated with aqueous acid. Subsequent treatment of C with 1,2-ethanethiol in toluene, catalysed by boron trifluoride, and followed by a Raney nickel reduction produced compound D.

D was found to be a symmetrical compound as well as a flammable gas. The addition of bromine water to A and B, independently, turned the solution from red to clear. Analysis of C revealed a molecular formula of C4H8O"

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My reasoning:

(C) is 2-butanone, (D) is butane

I think (A) is acetone - NaNH2 removes the alpha proton, the alpha carbon attacks the electrophile CH3-I.

Then (B) is 2-butanone also? Not sure what the acid is doing, perhaps it's there to react with Br-?

--

Is this viable? Or am I on the wrong track?

Thanks

[sjb]

"Reaction of compound A with sodium amide and ammonia followed by bromomethane yielded compound B.

Compound C is produced when B is isolated and treated with aqueous acid. Subsequent treatment of C with 1,2-ethanethiol in toluene, catalysed by boron trifluoride, and followed by a Raney nickel reduction produced compound D.

D was found to be a symmetrical compound as well as a flammable gas. The addition of bromine water to A and B, independently, turned the solution from red to clear. Analysis of C revealed a molecular formula of C4H8O"

----

My reasoning:

(C) is 2-butanone, (D) is butane

I think (A) is acetone - NaNH2 removes the alpha proton, the alpha carbon attacks the electrophile CH3-I.

Then (B) is 2-butanone also? Not sure what the acid is doing, perhaps it's there to react with Br-?

--

Is this viable? Or am I on the wrong track?

Thanks

Right sort of idea, but how else can you make ketones (for B  C) ?

[pfnm]

Another way might be:

Treat a terminal alkyne with a NaNH2 and NH3, to remove the hydrogen?

Eg Cmpoun A would be Propyne, deprotonated to form an alkyne carbanion...then the carbanion nucleophile attacks the CH3-I (electrophilic carbon) to form 2-butyne (compound B).

Then aqueous acid reacting with 2-butyne to form a methyl ketone...2-butanone (compound C).

Then protection with 1,2-ethanethiol and reduction to form butane (compound D)..

This sounds better I think, thanks sjb, is that the right track?

It would explain the Bromine water rxn too