242 K. R. HEBDITCH ET AL.
(C(CH3)2), 47.1 (C(CH3)2), 51.4 (SCH2), 51.6* (SCH2),
53.9 (CHNH2), 54.1* (CHNH2), 65.7 (t, J ¼ 21:0 Hz,
CD), 170.2 (CO). m/z (FAB+) 223.1225 (MH+
C9H19DNO3S requires 223.1227).
(R)-2-(tert-Butoxycarbonylamino)-3-(4-hydroxy-2-
methyl[4-2H1]pentan-2-ylthio) propanoic acid 14
(R)-2-(tert-Butoxycarbonylamino)-3-(2-methyl-4-oxopen-
tan-2-ylthio)-propanoic acid 13 (0.242 g, 0.76 mmol)
was dissolved in methanol (2 mL). Sodium borodeuter-
ide (0.03 g, 0.76 mmol) was added portionwise, then the
mixture was heated at reflux for 3 days. After cooling to
room temperature, the reaction was adjusted to pH 2
by the addition of a few drops of 2 M hydrochloric acid.
Water (10 mL) was added and the aqueous layer was
extracted three times with ethyl acetate (3 ꢁ 10 mL).
The combined organic fractions were dried over sodium
sulfate and the solvent removed in vacuo to give the title
compound (0.103 g, 42%) as a pale yellow oil: nmax
(film)/cmꢀ1 3333 (OH), 1710 (CO); 1H NMR (400 MHz;
CD3OD) d ¼ 1:17 (3H, s, CD(OH)CH3), 1.34 (6H, s,
C(CH3)2), 1.44 (9H, s, C(CH3)3), 1.62 (1H, d,
J ¼ 14:8 Hz, CHAHBCD), 1.69 (1H, d, J ¼ 14:8 Hz,
CHAHBCD), 2.85 (1H, m, SCHAHB), 2.96 (1H, m,
SCHAHB), 4.27 (1H, m, NHCH). 13C NMR (100 MHz;
CD3OD) d ¼ 25:6 CDCH3), 28.8 (C(CH3)3), 29.3
(C(CH3)2), 29.3* (C(CH3)2), 30.2* (C(CH3)2), 30.3
(C(CH3)2), 31.0 (CH2CD), 46.1 (C(CH3)2), 51.5 (SCH2),
55.2 (SCH2CH), 65.8 (t, J ¼ 21:6 Hz, CD), 80.7
(C(CH3)3), 157.7 (NCO), 174.4 (C(O)OH). m/z (FAB+)
323.1743 (MH+ C14H27DNO5S requires 323.1751).
(R)-2-Amino-3-(2-methyl-4-oxo[1,10-2H6]pentan-2-
ylthio)propanoic acid hydrochloric salt 18
l-Cysteine 16 (0.107 g, 0.88 mmol) and sodium carbo-
nate-decahydrate (0.05 g, 0.18 mmol) were dissolved in
a mixture of water (5 mL) and 1,4-dioxane (2 mL).
[2H10]Mesityl oxide 17 (0.11 g, 0.10 mmol) was added
and the reaction mixture was left to stir for 18 h. The
solution was acidified to pH 2 by the addition of a few
drops of 2 M hydrochloric acid and water was added
(10 mL). The aqueous solution was washed with diethyl
ether (10 mL), then concentrated in vacuo to give a
mixture of the title compound and cysteine in the ratio
0.7:1; 1H NMR (300 MHz; D2O) d ¼ 2:31 (3H, s,
C(O)CH3), 2.89 (1H, d, J ¼ 15:6 Hz, CHAHB), 2.96 (1H,
d, J ¼ 15:6 Hz, CHAHB), 3.21 (1H, dd, J ¼ 7:0 and
13.9 Hz, SCHAHB), 3.32 (1H, dd, J ¼ 4:6 and 13.9 Hz,
SCHAHB), 4.36 (1H, dd, J ¼ 4:6 and 7.0 Hz, H2NCH).
m/z (FAB+) 226.1380 (MH+ C9H12D6NO3S requires
226.1384).
REFERENCES
(R)-2-Amino-3-(4-hydroxy-2-methyl[4-2H1]pentan-2-
ylthio)propanoic acid hydrochloric salt 15
1. Darriet P, Tominaga, T, Lavigne V, Boidron JN,
Dubourdieu D. Flavour Frag J 1995; 10: 385–392.
2. Tominaga T, Furrer A, Henry R, Dubourdieu D.
Flavour Frag J 1998; 13: 159–162.
Hydrochloric acid (2 mL, 4 M solution in 1,4-dioxane)
was added to d-(R)-2-(tert-butoxycarbonylamino)-3-(4-
hydroxy-2-methylpentan-2-ylthio)propanoic acid 14
(0.09 g, 0.028 mmol) and the solution was left to stir
for 30 min. The 1,4-dioxane was then removed in vacuo.
The residue was passed though a short column of Li
Chroprep (40–63 mm) with water. The fractions were
freeze-dried to give the title compound (0.115 g) as a
white highly hydroscopic paste: nmax(film)/cmꢀ1 3347
(OH), 1736 (CO); 1H NMR (400 MHz; CD3OD) d ¼ 1:19
(3H, s, CD(OH)CH3), 1.36* (1.35H, s, C(CH3)A(CH3)B),
3. Tominaga T, Darriet P, Dubourdieu D. Vitis 1996;
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4. Tominaga T, Baltenweck-Guyot R, Peyrot des
Gachons C, Dubourdieu D. Am J Enol Vitic 2000;
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5. Murat ML, Tominaga T, Dubourdieu D. J Int Sci
Vigne Vin 2001; 35: 99–105.
6. Bouchilloux P, Darriet P, Henry R, Lavigne V,
Dubourdieu D. J Agric Food Chem 1998; 46:
3095–3099.
1.37 (1.65H, s, C(CH3)A(CH3)B), 1.38 (3H, s,
C
7. Tominaga T, Peyrot des Gachons C, Dubourdieu D.
J Agric Food Chem 1998; 46: 5215–5219.
8. Tominaga T, Murat ML, Dubourdieu D. J Agric
Food Chem 1998; 46: 1044–1048.
(CH3)A(CH3)B), 1.64 (0.55H, d, J ¼ 14:9 Hz, CHAHBCD
(OH)), 1.65* (0.45H, d, J ¼ 14:9 Hz, CHAHBCD(OH)),
1.74 (1H, d, J ¼ 14:9 Hz, CHAHBCD(OH)), 3.02* (0.45H,
dd, J ¼ 13:9 and 7.4 Hz, SCHAHB), 3.03 (0.55H, dd, J ¼
13:9 and 7.0 Hz, SCHAHB), 3.16 (1H, dd, J ¼ 4:2 and
13.9 Hz, SCHAHB), 4.15* (0.45H, dd, J ¼ 4:2 and
7.4 Hz, CHNH2), 4.21 (0.55H, dd, J ¼ 4:2 and 7.0 Hz,
CHNH2). 13C NMR (100 MHz; CD3OD) d ¼ 25:6*
(CH3CD(OH), 25.7 (CH3CH(OH), 29.1* (C(CH3)2), 29.3
(C(CH3)2), 29.5 (C(CH3)2), 29.8 (CH2CD(OH)), 46.9*
9. Schneider R, Kotseridis Y, Cray J-L, Augier C,
Baumes R. J Agric Food Chem 2003; 51: 3243–
3248.
10. Mateo-Vivaracho L, Ferreira V, Cacho J. J Chro-
matogr A 2006; 1121: 1–9.
11. Peyrot des Gachons C, Tominaga T, Dubourdieu D.
J Agric Food Chem 2000; 48: 3387–3391.
Copyright # 2007 John Wiley & Sons, Ltd.
J Label Compd Radiopharm 2007; 50: 237–243
DOI: 10.1002.jlcr