SYNTHESIS OF CYCLOBUTANE ANALOGUES OF THE ANTIVIRAL CYCLOPROPANE NUCLEOSIDE A-5021
摘要:
Cyclobutane analogues of the antiviral cyclopropane nucleoside A-5021 were synthesized from 1-cyano-1,2-bis(methoxycarbonyl)cyclobutane via 1) isolation of both diastereomers by crystallization, 2) reduction to aminodiol, 3) coupling with 2-amino-4,6-dichloropyrimidine, and 4) guanine ring formation. Despite their structural resemblance to A-5021, the compounds were devoid of antiherpetic activity.
Elimination and addition reactions. Part 43. Eliminative fission of cyclobutanes and the relationship between strain and reactivity in cyclobutanes and cyclopropanes
作者:Harold A. Earl、Charles J. M. Stirling
DOI:10.1039/p29870001273
日期:——
Eliminative fission of cyclobutanes has been compared with that of analogous cyclopropanes; reactivity differences of 103.7—104.8 have been determined. In both sets of compounds, mechanisms have been shown to involve rate-determining ringfission. The possibilities that the large reactivity differences between the comparably strained systems are due either to peculiarity in the cyclobutane structures
Eliminative ring fission of cyclobutanes: evaluation of acceleration by strain and the comparison with cyclopropanes
作者:Harold A. Earl、Donald R. Marshall、Charles J. M. Stirling
DOI:10.1039/c39830000779
日期:——
Cyclobutanes, by comparison with cyclopropanes, are reluctant to undergo eliminative ringfission; the very similar strain energies are released differently in the transition states for fission.