метанол -> x1 -> этан -> x2 -> x3 -> сложный эфир
1. CH3OH +HCl=CH3Cl+H2O
2CH3Cl +2Na=CH3-CH3 +2 NaCl
CH3-CH3=Ni=CH2=CH2 +H2
CH2=CH2+H2O=CH3-CH2OH
CH3-COOH+CH3-CH2OH=CH3-COOCH2-CH3 +H2O