Stereoselective reduction of enaminones to syn γ-aminoalcohols
One-pot reduction of enaminones to syn γ-aminoalcohols can be efficiently performed by lithium borohydride in the presence of cerium chloride as Lewis acid. Selectivities are very good with respect to classical reduction method of these products.
Bartoli, Giuseppe,Cupone, Giovanna,Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Procopio, Antonio,Tagarelli, Antonio
p. 7441 - 7444
(2007/10/03)
Convenient Procedure for the Reduction of β-Enamino Ketones: Synthesis of γ-Amino Alcohols and Tetrahydro-1,3-oxazines
γ-Amino alcohols 3 can be easily synthesized in very good yields by reduction of enaminones 1 with Na in PrOH-tetrahydrofuran.The reaction is fast, easy to perform, inexpensive and the easily accesible starting materials provide a convenient entry to γ-amino alcohols.The relative configuration assignment of the diastereomeric γ-amino alcohols obtained has been established by 1H and 13C NMR studies and unequivocally assigned by their cyclic tetrahydro-1,3-oxazine derivatives 4.
Syntheses d'aminoalcools-1,3 ou d'aminophenols-1,3 par reduction d'enaminones ou d'iminophenols par les hydrures metalliques. Etude structurale par infrarouge et RMN des aminoalcools-1,3 bisecondaires diastereomeres
Enaminones, obtained by reaction of a primary amine with a β-diketone, can take three tautomeric forms: keto-enamine Ia, keto-imine Ib and imino-enol Ic.In general the keto-enamine form Ia is the most stable.Thi