  We make some elementary observations concerning subcritically Stein fillable
contact structures on 5-manifolds. Specifically, we determine the
diffeomorphism type of such contact manifolds in the case the fundamental group
is finite cyclic, and we show that on the 5-sphere the standard contact
structure is the unique subcritically fillable one. More generally, it is shown
that subcritically fillable contact structures on simply connected 5-manifolds
are determined by their underlying almost contact structure. Along the way, we
discuss the homotopy classification of almost contact structures.

Geometric Topology;Symplectic Geometry