Asymmetric Diels-Alder reactions of chiral cyclopropylidene imide dienophiles: preparation of gem-dimethyl- and spirocyclopropane norbornyl carboxylic acids.
A highly efficient strategy has been developed for the rapid asymmetric synthesis of gem-dimethyl and spirocyclopropyl norbornyl carboxylic acids. The key transformation involved the unprecedented asymmetric Diels-Alder reaction of highly reactive beta,beta-cyclopropyl-alpha,beta-unstaturated N-acyloxazolidinones with cyclopentadiene affording the adducts in high yield and de.
Department of Process Research, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065, USA. jeffrey_kuethe@merck.com
Jeffrey T
JT
Kuethe
Dalian
D
Zhao
Guy R
GR
Humphrey
Michel
M
Journet
Arlene E
AE
McKeown
D002264:Carboxylic Acids / Q000138:chemical synthesis*; D003521:Cyclopropanes / Q000737:chemistry; D007094:Imides / Q000737:chemistry; D009636:Norbornanes / Q000138:chemical synthesis*; D013141:Spiro Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism
D002264:Carboxylic Acids; D003521:Cyclopropanes; D007094:Imides; D009636:Norbornanes; D013141:Spiro Compounds