(Adamantan-1-yl)(phenylsulfanyl)methanone

Two independent molecules (A and B) comprises the asymmetric unit of the title ester, C17H20OS. The phenyl ring is inclined with respect to the thiocarboxyl group, forming dihedral angles of 58.95 (6) (in molecule A) and 62.28 (6)° (in molecule B). In each independent molecule, one adamantyl methylene C atom is nearly coplanar with the thiocarboxyl group. The major difference between molecules A and B relates to the relationship between the S atom and the coplanar adamantyl methylene C atom [Ca—Cq—Cc—S torsion angles = 178.25 (8) and 6.81 (13)°, respectively; Ca = adamantyl methylene C atom, Cq = quaternary C atom and Cc = carbonyl C atom], whereby the S atom in molecule A has an anti relationship with the methylene C atom and in molecule B, the S atom is syn. In the crystal, C—H⋯π interactions are formed leading to supramolecular layers in the ac plane.

Two independent molecules (A and B) comprises the asymmetric unit of the title ester, C 17 H 20 OS. The phenyl ring is inclined with respect to the thiocarboxyl group, forming dihedral angles of 58.95 (6) (in molecule A) and 62.28 (6) (in molecule B). In each independent molecule, one adamantyl methylene C atom is nearly coplanar with the thiocarboxyl group. The major difference between molecules A and B relates to the relationship between the S atom and the coplanar adamantyl methylene C atom [C a -C q -C c -S torsion angles = 178.25 (8) and 6.81 (13) , respectively; C a = adamantyl methylene C atom, C q = quaternary C atom and C c = carbonyl C atom], whereby the S atom in molecule A has an anti relationship with the methylene C atom and in molecule B, the S atom is syn. In the crystal, C-HÁ Á Á interactions are formed leading to supramolecular layers in the ac plane.   Table 1 Hydrogen-bond geometry (Å , ).

Experimental
Cg1 and Cg2 are the centroids of the C12-C17 and C29-C34 benzene rings, respectively.

Tiekink Comment
It is widely known that thioesters are useful building blocks for organic transformations, for example thioesters are important in many areas of organic chemistry, particularly in peptide, protein, and β-lactam synthesis (Shah et al., 2002).
Two independent molecules comprise the asymmetric unit of (I), Fig. 1. As seen from the overlay diagram, Fig. 2, there are non-trivial differences between the molecules when the S1-containing molecule is superimposed with the inverted S2containing molecule. The dihedral angle between the plane through the COS atoms and the S-bound phenyl ring is 58.95 (6)° for the S1-containing molecule and 62.28 (6)° for the S2-containing molecule. There is a more dramatic difference in the relative orientations between the COS residue and the adamantyl group. This is best quantified in the values of the C2 -C1-C11-S1 and C25-C18-C28-S2 torsion angles of 178.25 (8) and 6.81 (13)°, respectively, i.e. where there is an almost co-planar relationship between the S and one methylene-C atom. The difference arises in the the S1 atom has anti relationship with the co-planar methylene-C atom and the S2 atom has a syn relationship.
In the crystal packing, C-H···π interactions are formed with the C12-C17 ring forming two such interactions, Table 1.
The result is the formation of a supramolecular layer in the ac plane with the adamantyl groups inter-digitating along the b axis, Fig. 2.

Experimental
Trifluoroacetic acid (0.4 equiv.) was added drop-wise to a stirred solution of 1-adamantane carboxylic acid (1 equiv.) and thiophenol (1 equiv) in dry CH 3 CN (0.01 mol/L) over a period of 15 min. at room temperature. After being stirred for 5 h at 333 K, the mixture was quenched by adding ammonium chloride solution (5 ml), extracted with ethylacetate, washed with brine and dried over anhydrous Na 2 SO 4 . The product, obtained after evaporation of the solvent, was purified by column chromatography using mixture of hexane and CHCl 3 as eluent.

Figure 1
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.  Superimposition of the S1-containing molecule (red) and the inverted S2-containing molecule (blue) in (I). The COS moieties have been superimposed.