A Novel Sequential Aminodiene Diels−Alder Strategy for the Rapid Construction of Substituted Analogues of Kornfeld's Ketone
摘要:
[GRAPHICS]Through a novel sequence of aminodiene Diels-Alder reactions, amidofurans 18a-c were converted to tricyclic ketones 21a-c in moderate to good yields. Ketone 21a could be converted to Uhle's ketone (6) by cleaving the tert-butyl carbamate and oxidatively removing the methyl ester. Tricycle 21a readily underwent bromination to give 22. Formation of the corresponding enol triflate 25 followed by carbonylation gave ester 27, which was then coupled with N-methyl propriolamide to furnish 26.
A Novel Sequential Aminodiene Diels−Alder Strategy for the Rapid Construction of Substituted Analogues of Kornfeld's Ketone
作者:Scott K. Bur、Albert Padwa
DOI:10.1021/ol0268992
日期:2002.11.1
[GRAPHICS]Through a novel sequence of aminodiene Diels-Alder reactions, amidofurans 18a-c were converted to tricyclic ketones 21a-c in moderate to good yields. Ketone 21a could be converted to Uhle's ketone (6) by cleaving the tert-butyl carbamate and oxidatively removing the methyl ester. Tricycle 21a readily underwent bromination to give 22. Formation of the corresponding enol triflate 25 followed by carbonylation gave ester 27, which was then coupled with N-methyl propriolamide to furnish 26.
Sequential Aminodiene Diels−Alder Approach to the Ergoline Skeleton
作者:Albert Padwa、Scott K. Bur、Hongjun Zhang
DOI:10.1021/jo0508797
日期:2005.8.1
diene. The presence of this activating group not only prevents the isomerization of the advanced ergoline intermediate to a naphthalene but can also be leveraged for an oxidation to provide Uhle's ketone (13). The easily formed Kornfeld ketone analogue 25 was readily transformed into the corresponding triflate 41 by the action of triflic anhydride and a base. Oxidative addition of vinyl triflate 41 to Pd(0)