Studies on asymmetric synthesis of bicyclomycin precursors. A chemoenzymatic route to chiral 2,5-diketopiperazines and 2-oxa-bicyclo[4.2.2]decane-8,10-diones
摘要:
A novel asymmetric route to bicyclomycin analogues, 2-oxa-bicyclo[4.2.2]decane-8,10-diones, is described. The key chiral synthons 3-(omega-hydroxyalkyl)-2,5-diketopiperazines 3a-c were obtained via enzymatic kinetic resolution of their respective acetates 2a-c using hydrolases (up to >98% ee, E > 200). The chiral 2,5-diketopiperazines were then transformed into their bicyclic derivatives in a stereospecific manner. Circular dichroism and NMR studies were performed to determine the absolute and relative configuration of the obtained products. The biocatalytic approach gave high stereoselectivities in comparison to the chiral pool synthesis from glutamic acid (58% ee) and thus demonstrated the ability of hydrolases to discriminate a remote stereocenter. (C) 2017 Elsevier Ltd. All rights reserved.
Studies towards the synthesis of bicyclomycin precursors: Synthesis of<i>N,N</i>′-disubstituted 2,5-diketopiperazines in solution and on solid phase
作者:Anna Fryszkowska、Ryszard Ostaszewski
DOI:10.1002/jhet.5570450321
日期:2008.5
3-(hydroxyalkyl)-N,N′-disubstituted 2,5-diketopiperazine derivatives - compounds required for the bicyclomycin analogues preparation - has been studied. The use of various oxo components in the Ugi multicomponent reaction (U-MCR) has been evaluated. The first example of an semicyclic O,O-acetal employed as an aldehyde equivalent in the U-MCR has been reported. The preparation and the synthetic application of
Studies on asymmetric synthesis of bicyclomycin precursors. A chemoenzymatic route to chiral 2,5-diketopiperazines and 2-oxa-bicyclo[4.2.2]decane-8,10-diones
A novel asymmetric route to bicyclomycin analogues, 2-oxa-bicyclo[4.2.2]decane-8,10-diones, is described. The key chiral synthons 3-(omega-hydroxyalkyl)-2,5-diketopiperazines 3a-c were obtained via enzymatic kinetic resolution of their respective acetates 2a-c using hydrolases (up to >98% ee, E > 200). The chiral 2,5-diketopiperazines were then transformed into their bicyclic derivatives in a stereospecific manner. Circular dichroism and NMR studies were performed to determine the absolute and relative configuration of the obtained products. The biocatalytic approach gave high stereoselectivities in comparison to the chiral pool synthesis from glutamic acid (58% ee) and thus demonstrated the ability of hydrolases to discriminate a remote stereocenter. (C) 2017 Elsevier Ltd. All rights reserved.