Kw. Laue et G. Haufe, 3-BROMO-2-FLUOROPROPENE - A FLUORINATED BUILDING-BLOCK - 2-FLUOROALLYLATION OF GLYCINE AND ALANINE ESTER IMINES, Synthesis, (10), 1998, pp. 1453-1456
3-Bromo-2-fluoropropene (4) is prepared in a new three-step synthesis
from ammonium alpha-fluoroacrylate (1) in 31% overall yield. Glycine a
nd alanine ester imines are efficiently alkylated by 4 to give, after
deprotection, 2-amino-4-fluoropent-4-enoic acid (9) in 63% overall yie
ld, and the alpha-methylated derivative 13 in 26% overall yield, respe
ctively. Preliminary results indicate that 4 is potentially a new alph
a-carbonyl cation equivalent.