
169Biologically Important Amino Acids
O
Cl
O
NH(CH
2
)
m
CO
2
Me
3
SiO
NH
2
(CH
2
)
m
CO
2
Me
m = 1–7
269
270
(–)-Galantinic acid (6-amino-3,5,7-trihydroxyheptanoic acid, 277) is a structural
component of galantin I, a peptide antibiotic.
249
Amino acids can be converted to
aldehydes, as amply demonstrated in previous sections. These precursors can
also be used for the preparation of polyhydroxy amino acids. Horner-Wadsworth-
Emmons olenation
250,251
of 271 gave 272.
252
Epoxidation, oxidation, and Wittig
olenation
253
gave 273. Isomerization of the double bond out of conjugation, to give
274, was followed by treatment with base and gave lactone 275. Introduction ...