Abstract The title aldehyde (1) was obtained in 69% isolated yield by chlorination of 4- chlorobutanol in the presence of dimethylformamide. 3, 3-Dichloro-2-hydroxytetrahydrofuran (3a) or the 2-alkoxyderivatives 3b and 3c were produced by treating the hydrate 2a or the hemiacetals 2b and 2c resp. with base. With aqueous ammonia 1 rapidly formed the hemiaminal which then slowly afforded 3, 3-dichloro-σ1-pyrroline (4). In a rapid reaction ...
