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P. Bataille et al. / Tetrahedron: Asymmetry 9 (1998) 2181–2192
3.21. (R,R)-(−)-2-[1-Methyl-2-(1-phenylhexyl)hydrazono]butan-1-ol (R,R)-(−)-30d
Starting from magnesium (0.471 g), 1-bromopentane (2.4 ml) in ether (20 ml), and the hydrazone
(R)-(−)-29 (0.400 g; 1.94 mmol) in ether (5 ml), the above procedure led to the hydrazine (R,R)-(−)-30d
(0.44 g; 81.4%), [α]D −0.8 (c 1.2, MeOH) and d.e.=100% (1H and 13C NMR). 1H NMR (CDCl3) δ: 0.82
(t, 3H); 0.83 (t, 3H); 1.0–1.80 (m, 10H); 2.43 (s, 3H); 2.47–2.50 (m, 1H); 3.34–3.44 (dd, 1H); 3.59–3.66
(dd, 1H); 3.72–3.79 (dd, 1H); 7.20–7.40 (m, 5H). 13C NMR (CDCl3) δ: 10.89 (q), 13.95 (q), 17.38 (t);
22.47 (t), 25.89 (t), 31.84 (t), 34.92 (t), 40.16 (q), 62.86 (d), 63.08 (t), 68.17 (d), 127.24 (d), 127.75 (2d),
128.24 (2d), 143.02 (s).
3.22. (R,R)-(−)-2-[1-Methyl-2-(1-phenylheptyl)hydrazono]butan-1-ol (R,R)-(−)-30e
Starting from magnesium (0.238 g), 1-bromohexane (1.36 ml) in ether (10 ml), and the hydrazone
(R)-(−)-29 (0.200 g; 0.97 mmol) in ether (2 ml), the above procedure led to the hydrazine (R,R)-(−)-30e
(0.128 g; 45.2%), [α]D −4.3 (c 0.8, MeOH) and d.e.=100% (1H and 13C NMR). 1H NMR (CDCl3) δ:
0.82–0.86 (m, 6H); 1.10–2.0 (m, 12H); 2.43 (s, 3H); 2.40–2.50 (m, 1H); 3.37–3.41 (dd, 1H); 3.61–3.64
(dd, 1H); 3.74–3.77 (dd, 1H); 7.10–7.40 (m, 5H). 13C NMR (CDCl3) δ: 10.39 (q), 13.48 (q), 16.92 (t),
22.02 (t), 25.70 (t), 28.81 (t), 34.47 (t), 39.65 (q), 62.38 (d), 62.58 (t), 69.12 (d), 126.76 (d), 127.25 (2d),
127.75 (2d), 143.27 (s).
3.23. (R,R)-(−)-2-[1-Methyl-2-(1-phenyloctyl)hydrazono]butan-1-ol (R,R)-(−)-30f
Starting from magnesium (0.238 g), 1-bromoheptane (1.35 ml) in ether (10 ml), and the hydrazone
(R)-(−)-29 (0.200 g; 0.97 mmol) in ether (2 ml), the above procedure led to the hydrazine (R,R)-(−)-30f
1
(0.208 g; 70%), [α]D −2.8 (c 1.07, MeOH) and d.e.=100% (1H and 13C NMR). H NMR (CDCl3) δ:
0.83 (t, 3H); 0.85 (t, 3H); 1.10–1.90 (m, 14H); 2.43 (s, 3H); 2.40–2.50 (m, 1H); 3.37–3.41 (dd, 1H);
3.61–3.64 (dd, 1H); 3.74–3.77 (dd, 1H); 7.10–7.40 (m, 5H). 13C NMR (CDCl3) δ: 10.91 (q), 14.03 (q),
17.44 (t), 22.57 (t), 26.27 (t), 29.15 (t), 29.64 (t), 31.75 (t), 35.00 (t), 40.18 (q), 62.90 (d), 62.96 (t), 68.22
(d), 127.27 (d), 127.78 (2d), 128.27 (2d), 143.06 (s).
3.24. (R,R)-(−)-2-[1-Methyl-2-(1-phenylnonyl)hydrazono]butan-1-ol (R,R)-(−)-30g
Starting from magnesium (0.471 g), 1-bromooctane (3.35 ml) in ether (20 ml), and the hydrazone (R)-
(−)-29 (0.400 g; 1.94 mmol) in ether (5 ml), the above procedure led to the hydrazine (R,R)-(−)-30g
(0.437 g; 70.4%), [α]D −2.8 (c 1.1, MeOH) and d.e.=100% (1H and 13C NMR). 1H NMR (CDCl3) δ:
0.84 (t, 3H); 0.86 (t, 3H); 1.10–1.90 (m, 16H); 2.43 (s, 3H); 2.40–2.50 (m, 1H); 3.37–3.41 (dd, 1H);
3.61–3.64 (dd, 1H); 3.74–3.77 (dd, 1H); 7.10–7.40 (m, 5H). 13C NMR (CDCl3) δ: 10.33 (q), 13.47 (q),
16.82 (t), 22.00 (t), 25.67 (t), 28.60 (t), 28.84 (t), 29.07 (t), 31.19 (t), 34.40 (t), 39.59 (q), 62.90 (d), 62.53
(t), 67.63 (d), 127.68 (d), 127.78 (2d), 127.87 (2d), 143.11 (s).
3.25. General procedure for the hydrogenolysis of the hydrazines 30: preparation of the (R)-1-phenyl-
1-alkanamines (R)-31
The trisubstituted hydrazine 30a–g in ethanol was hydrogenolyzed in the presence of conc. HCl and
10% Pd–C under hydrogen (6 bar) at 55–65°C for 16 h. After filtration and evaporation, the residue
was treated with 32% aqueous ammonia solution until basic, and the mixture was extracted three times