The first enantioselective organocatalytic Mukaiyama-Michael reaction: a direct method for the synthesis of enantioenriched gamma-butenolide architecture.
The first enantioselective organocatalytic Mukaiyama-Michael reaction using alpha,beta-unsaturated aldehydes has been accomplished. The use of iminium catalysis has provided a new strategy for the enantioselective addition of 2-silyloxy furans to unsaturated aldehydes to generate a variety of butenolide systems, an important chiral synthon found among many natural isolates. The (2S,5S)-5-benzyl-2-tert-butyl-imidazolidinone amine catalyst has been found to mediate the conjugate addition of a wide variety of substituted and unsubstituted silyloxy furans to unsaturated aldehydes. A diverse range of aldehyde substrates can be accommodated in this new organocatalytic transformation. Application of this new asymmetric technology to the enantioselective total synthesis of spiculisporic acid and the corresponding 5-epi-spiculisporic acid analogue is also discussed.
Brown
Sean P
SP
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Goodwin
Nicole C
NC
MacMillan
David W C
DW
D015107:4-Butyrolactone / Q000031:analogs & derivatives; D000447:Aldehydes / Q000737:chemistry; D002384:Catalysis; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D008958:Models, Molecular; D013237:Stereoisomerism
D000447:Aldehydes; D005663:Furans; D007093:Imidazoles; C004511:butenolide; D015107:4-Butyrolactone