3-Methoxythiophene-2-methanol 2 undergoes condensation with elimination of
water and formaldehyde under acidic conditions to give bis(3-methoxy-2-thie
nyl)methane 3 and a further product resulting from reaction of 3 with the t
hienylmethyl carbocation; the other electron-rich thiophenemethanols 8 and
10 react similarly.