Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations
作者:Paul Hommes、Hans-Ulrich Reissig
DOI:10.3762/bjoc.12.112
日期:——
The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a-e, the corresponding beta-ketoenamines 2a-e were converted into different beta-ketoenamides 3a-g by N-acylation with 2-pyridinecarboxylic acid derivatives. These beta-ketoenamides were treated with a mixture of TMSOTf and Hunig's base to promote the cyclocondensation to 4-hydroxypyridine
A New and Flexible Synthesis of 4-Hydroxypyridines: Rapid Access to Caerulomycins A, E and Functionalized Terpyridines
作者:Jyotirmayee Dash、Hans-Ulrich Reissig
DOI:10.1002/chem.200900939
日期:2009.7.13
ammonia, and carboxylic acids are the precursors for the efficient synthesis of 4‐hydroxypyridines and the corresponding nonaflate derivatives. This provides simple and practical access to a variety of highly substituted pyridine derivatives, including antibiotic natural products such as caerulomycins A, E and functionalizedterpyridines (see scheme).