In the previous problem, we saw that an acetylide ion can attack a variety of electrophiles. In Chapter 20, we will see that a C=O bond can also function as an electrophile. Consider the following reaction between an acetylide ion (the nucleophile) and a ketone (the electrophile):

The acetylide ion attacks the ketone, generating an alkoxide ion. After the reaction is complete, a proton source is used to protonate the alkoxide ion. In a synthesis, these two steps must be shown separately, because the acetylide ion will not survive in the presence of H₃O⁺. Using this information, propose a plausible synthesis for allyl alcohol, using acetylene as your only source of carbon atoms:

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Н-СЕС: 'R н :ОН н R- -R R- R н