“…[19,20a] When benzene is replaced by the noncarcinogenic toluene, the pressure should be reduced to 250 mbar in order to run the reaction at lower temperature and to avoid partial decomposition of the product. The aforementioned auxiliary has been applied earlier for syntheses of other amino acids, [21Ϫ23] α,α-disubstituted α-amino acids, [20,21] α-aminophosphonic acids, [24] and optically active amines. [25] Alkylation of the Schiff base 1a, derived from (ϩ)-(R,R,R)-2-hydroxy-3-pinanone, with 1-bromo-2-fluoroethane (2) after deprotonation with LDA succeeded with a diastereoselectivity of 90% (Scheme 1, Table 1).…”