Selective Michael-aldol reaction by use of sterically hindered aluminum aryloxides as Lewis acids: an easy approach to cyclobutane amino acids.
A formal [2 + 2] cycloaddition of 2-amidoacrylates with monosubstituted donor olefins, including its asymmetric version, is described. The stereoselectivity of this reaction can be modulated by the use of sterically hindered aluminum aryloxides or methylaluminoxane as Lewis acids. The reaction was applied to the synthesis of both stereoisomers of 2-benzyloxycyclobutane-alpha-amino acid, which are protected serine analogues c(4)Ser(OBn).
Avenoza
Alberto
A
Universidad de La Rioja, Departamento de Química, UA-CSIC E-26006 Logroño, Spain. alberto.avenoza@dq.uniroija.es
Busto
Jesús H
JH
Canal
Noelia
N
Peregrina
Jesús M
JM
Pérez-Fernández
Marta
M
D000475:Alkenes / Q000737:chemistry; D000535:Aluminum / Q000737:chemistry; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D012694:Serine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000475:Alkenes; D000596:Amino Acids; D012694:Serine; D000535:Aluminum