  The circumstellar environments of objects on the asymptotic giant branch and
beyond are rich in molecular species. Nevertheless, methanol has never been
detected in such an object, and is therefore often taken as a clear signpost
for a young stellar object. However, we report the first detection of CH3OH in
a post-AGB object, HD101584, using ALMA. Its emission, together with emissions
from CO, SiO, SO, CS, and H2CO, comes from two extreme velocity spots on either
side of the object where a high-velocity outflow appears to interact with the
surrounding medium. We have derived molecular abundances, and propose that the
detected molecular species are the effect of a post-shock chemistry where
circumstellar grains play a role. We further provide evidence that HD101584 was
a low-mass, M-type AGB star.
