701
|
Tori K, Aono K, Hata Y, Muneyuki R, Tsuji T, Tanida H. NMR studies of bridged ring systems. IX anomaly in magnetic shielding of bridge-methylene protons in norbornene and benzonorbornene evidenced by proton spin-decoupling and deuteration methods. Tetrahedron Lett 1966. [DOI: 10.1016/s0040-4039(01)99622-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
702
|
Hata Y, Takashima T, Kitamura H. Stereological studies on several ducts and vessels by injection method of acrylic resin. XIV. On the A. alveolaris superior posterior of rabbit. Okajimas Folia Anat Jpn 1965; 41:213-20. [PMID: 5318703 DOI: 10.2535/ofaj1936.41.2-3_213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
703
|
Tori K, Hata Y, Muneyuki R, Takano Y, Tsuji T, Tanida H. N.M.R. STUDIES OF BRIDGED RING SYSTEMS: II. UNUSUAL MAGNETIC DESHIELDING EFFECT ON THE BRIDGE METHYLENES OF NORBORNADIENE AND BENZONORBORNADIENE. CAN J CHEM 1964. [DOI: 10.1139/v64-135] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proton magnetic resonance spectra of some norbornane derivatives having double bonds and (or) a benzene ring in the skeleton were studied. Differences in the chemical shifts between the bridge methylenes of norbornene and benzonorbornene and that of norbornane result from the diamagnetic anisotropy effect of a double bond or a benzene ring being in good agreement with the values calculated theoretically. However, in the norbornadiene derivatives which have two double bonds or one olefinic double bond with a benzene ring in a part of the skeleton, the signals of their bridge methylenes show extraordinarily larger downfield shifts by about 0.8 p.p.m. than those expected from the additive shielding due to each π-electron system. This anomaly is not observed in bicyclo[2.2.2]octane ring series. A large transannular interaction between two π-electron systems in that system would be a major contribution to the above anomaly.
Collapse
|