When acetylene is passed into methanol at 160-200°C in the presence of a small amount of potassium methoxide and under pressure, the following is formed:

When acetylene is passed into methanol at 160°00 -200°C in the presence of a small amount(I-2%) of potassium methoxide and under pressure just high enough to prevent boiling, methyl vinyl ether is formed.The mechanism is believed to involve nucleophilic attack in the first step.HC≡CH+CH3O⊖→C⊖H=CHOCH3⟶CH3OHCH2=CH2OCH3+CH3O⊖                                                                                   Methyl vinyl ether