An efficient entry to optically active anti- and syn-beta-amino-alpha-trifluoromethyl alcohols.
The reaction of chiral 5,6-dihydro-2H-1,4-oxazin-2-ones with TMSCF3 in the presence of a suitable activator leads to trifluoromethyl lactols, which can be selectively reduced to anti-beta-amino-alpha-trifluoromethyl alcohols. The corresponding syn diastereoisomers are obtained when the starting imines are reduced and the nitrogen atom is conveniently protected. In addition, a novel rearrangement of the CF3 group in the lactol intermediates has been observed. This represents a formal CF3 addition to the imine function in the starting substrates.
Fustero
Santos
S
Departamento de Química Orgánica, Universidad de Valencia, E-46100 Burjassot, Spain. santos.fustero@uv.es
Albert
Laia
L
Aceña
José Luis
JL
Sanz-Cervera
Juan F
JF
Asensio
Amparo
A