RESUMEN
In the title compound, C18H22O4, the cyclo-hexane and cyclo-hexa-none rings adopt normal chair and half-chair conformations, respectively. The dioxolane ring is almost planar, with an r.m.s. deviation of 0.094â (3)â Å. In the crystal, mol-ecules are connected by O-Hâ¯O hydrogen bonds, forming 21 helical chains along the a-axis direction. The chains are further connected by C-Hâ¯O hydrogen bonds.
RESUMEN
The title compound, C(11)H(10)Cl(2), is a useful inter-mediate for the synthesis of 1H-cyclo-propa[b]naphthalene. Strain in the mol-ecule is evidenced by the fact that the cyclo-hexane ring is essentially planar and nearly coplanar with the benzene ring [dihedral angle 1.87â (18)°], and the cyclo-propyl ring is almost perpendicular to the cyclo-hexane ring [dihedral angle 70.99â (12)°]. The mol-ecules are loosely connected into one-dimensional chains by inter-molecular Clâ¯Cl inter-actions with a distance of 3.571â (1)â Å. The centroid-to-centroid distance between stacked benzene rings is ca 5.89â Å, indicating that no π-π stacking exists in the crystal structure.
RESUMEN
A linear sweep adsorptive stripping voltammetric method (AdS-LSV) for the determination of tobramycin (TOB) has been proposed for the first time. The method is based on the formation of the voltammetrically active iso-butyraldehyde derivative of TOB and the electrochemical behavior of TOB iso-butyraldehyde derivative has been studied. TOB iso-butyraldehyde derivative exhibits a sensitive cathodic peak at -1.40 V (versus SCE) in a medium of B-R buffer (pH 9.8) with a scan rate of 90 mVs(-1) after a preconcentration period of 120 s at -1.10 V (versus SCE). The linear concentration range of application was 6.87 x 10(-9) - 3.44 x 10(-7) mol L(-1) of TOB, with a relative standard deviation of 4.4% (for a level of 1.0 x 10(-7) mol L(-1)) and a detection limit of 3.44 x 10(-9) mol L(-1). The method was applied to the direct determination of TOB in injectable formulations and spiked urine and serum samples.