Rotational
emission from vibrationally excited molecules are responsible
for a large fraction of lines in the spectra of interstellar molecular
clouds. Vinyl alcohol (VA) has two rotamers that differ in energy
by 6.4 kJ/mol, both of which have been observed toward the molecular
cloud, Sagittarius B2(N) [Turner and Apponi, Astrophys. J.2001561207]. Previously,
we reported an analysis of the far-infrared spectrum of the higher
energy rotamer, anti-VA [Bunn et al. Astrophys. J.201784767], yielding rotational
and higher order distortion constants in the first excited vibrational
state, and here, we report an analysis of the far-infrared spectrum
of the lower energy rotamer, syn-VA, whose spectrum
is significantly more complicated on account of Coriolis interactions
that result in perturbations to the rovibrational spectrum. We account
for those perturbations with the inclusion of Coriolis coupling constants
in the fit, which couples the first excited OH torsional (ν15) and CCO bending (ν11) states. Inclusion
of them resulted in more physically meaningful rotational and centrifugal
distortion constants, and allows for accurate pure rotational line
predictions to be made up to high energies. These will be particularly
useful in searches for vibrationally excited syn-VA
toward warm regions of interstellar molecular clouds, where we predict
that it may be significantly abundant.