Starting with ethyne and $2-$methyl$-$propene, how do you synthesize $2-$methyl$-$pentan$-3-$one? You can use any reagent you like in as many steps necessary. Please provide all intermediates. All carbon atoms must come from the starting materials and you can use as many equivalents of them as needed. No mechanisms required, just the synthesis steps. Note: the photo shows a retroactive scheme.