<sup>17</sup>
O,
<sup>13</sup>
C and
<sup>1</sup>
H NMR spectra of 1,2‐dialkoxyethenes
作者:Esko Taskinen
DOI:10.1002/(sici)1097-458x(199808)36:8<573::aid-omr343>3.0.co;2-#
日期:1998.8
The O-17,C-13 and H-1 NMR spectra of a number of 1,2-dialkoxyethenes (ROCH)-O-1=CHOR2 were recorded. The O atoms, in particular those of the E forms, are strongly shielded relative to the O-17 nuclei of the corresponding alkyl vinyl ethers ROCH=CH2. Moreover, in compounds of the type ROCH=CHOMe, the difference delta(O-17)(z)-delta(O-17)(E) of the MeO group decreases and that of the RO group increases with increasing bulkiness of R. These trends probably arise from changes, with the size of the alkyl group R, in the stereochemistry of the RO group of the E-isomer about the O-C(sp(2)) bond, whereas the stereochemistry of the Z-form seems to be independent of the size of R. Additional information on the stereochemistry of the title compounds is provided by their C-13 and H-1 NMR spectra. (C) 1998 John Wiley & Sons, Ltd.