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Optically Active 4‐Substituted 5‐Nitropentan‐2‐ones: Valuable Chiral Building Blocks for the Stereocontrolled Construction of Spiro‐Pyrazolone Scaffolds with Five Contiguous Stereogenic Centers
Author(s) -
Sun Jiao,
Jiang Cuiping,
Zhou Zhenghong
Publication year - 2016
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201501449
Subject(s) - stereocenter , pyrazolones , pyrazolone , chemistry , optically active , aldol reaction , yield (engineering) , combinatorial chemistry , stereochemistry , enantioselective synthesis , organic chemistry , catalysis , materials science , metallurgy
The application of readily available optically active 4‐substituted 5‐nitropentan‐2‐ones as chiral building blocks in the stereocontrolled construction of spiro‐pyrazolone scaffolds was investigated. In the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (1 equiv.) optically active 4‐substituted 5‐nitropentan‐4‐ones exhibited excellent chiral inducing abilities in the diastereoselective cascade Michael/aldol reaction with a wide range of unsaturated pyrazolones to generate the corresponding biologically significant spiro‐pyrazolone derivatives with five contiguous stereocenters in acceptable to good yield with high levels of diastereoselectivity.