A Co(I)-catalysed condensation of allylidenedipivalate with aldehydes to give (Z)-4-hydroxybut-1-enyl pivalates in 62 to 87% isolated yields, is reported. Reactions are run in acetonitrile at 0 or 25 °C depending on the nature of the aldehyde, and exploiting the Co(II)/Zn(0) redox couple for the preparation of the catalytic Co(I) species.