O.r.d. studies of β-amino ketones. I. The crystal structure and absolute configuration of (+)-(1-methyl-3-benzoyl-3-bromoacetoxypiperidine hydrobromide)

O.r.d. studies of β-amino ketones. IV. The crystal and absolute configuration of (+)-[1,3-dimethyl-3-benzoylpiperidine methiodide]

“…Since C(5) is closer to the optically active chromophore, it should dominate the sign of the CEC. Thus, the observed positive CEC for this protonated, exocyclic, fl-amino ketone [(I) HC1] like others in this series reported to date (Hite & Craven, 1973;Hite & Soares, 1973) is consistent with antioctant behavior. forward octants signed for the x and y projections, and the four rear octants signed for the z projection.…”

“…3) and the O-C(8)-C(3)-C(2) torsion angle is -24 °. The O-C(2) and O-C.~x(1) interatomic distances of 2.81 and 3.01 A, respectively, suggest electrostatic attraction between O and the cationic center (Hite & Craven, 1973;Hite & Soares, 1973). The effects of steric crowding in the 1,3-(aa) system are observable in the opening of the C(2)-N-Cax(1), C(2)-C(3)-C(8) and C(4)-C(3)-C(8) bond angles of 115, 114 and 115 °, respectively, in the closing of the C(7)-C(3)-C(8) and C(2)-C(3)-C(7) bond angles of 105 and 103 °, respectively, in the C(2)-C(3)-C(8)-O torsion angle of -24 °, and in the ring conformation angles (Fig.…”

Stereochemical aspects of local anesthetic action. II. The crystal structure of cocaine methiodide

“…In solution, the cation is remote from counter ions. Thus, the boat conformation may be stabilized by electrostatic interactions (Craven & Hite, 1973;Ruble, Hite & Soares, 1976, and previous papers in that series) between the benzoate oxygen atoms and the cationic center (< 3.0 A) particularly in the apolar environment of the nerve membrane where local anesthetics are known to act and where such interactions would be more significant than in water. Thus, since the crystal structure of (IV) hydrochloride may lack biological significance, it was of interest to determine the structures of (IV) methiodide and of normethyl-(IV) salts.…”

“…Thus the 0(4) to C(1) intramolecular distance, governed by electrostatic attraction (Craven * Rw=[Ew(Ifobsl-Ifc,,cl) The absolute configuration of cocaine reported by Gabe & Barnes (1963) was that of 2S-methoxycarbonyl-3R-benzoyloxytropane, and thus their observed C(1)-C(2)-C(15)-O(4) torsion angles is + 17 °. SHORT STRUCTURAL PAPERS & Hite, 1973;Hite & Craven, 1973;Hite & Soares, 1973) is slightly longer in the methiodide salt (2.63 vs 2.84/~). Packing of the molecules is shown in Fig.…”