Asymmetric Reduction of Prochiral Ketones
693
IR (KBr), n: 3333, 3273, 2951, 1739, 1490, 1443, 1320, 1142, 1063, 969, 747,
1
697 cm21; H NMR: d 7.67–7.13 (m, 15H), 5.23 (d, J ¼ 9.3 Hz, 1H), 5.00
(m, 1H), 3.22 (br, 1H), 2.99 (d, J ¼ 14.1 Hz, 1H), 2.79 (dd, J ¼ 8.7,
14.1 Hz, 1 H), 2.28 –1.61 (m, 8H), 1.35–1.28 (m, 1H), 0.79 (s, 3H), 0.49
(s, 3H). Anal. calcd. for C31H35NO4S: C, 71.92%; H, 6.82%; N, 2.71%.
Found: C, 71.77%; H, 6.89%; N, 2.82%.
N-(1S)-(1,2,2-Tribenzyl-2-hydroxy-ethyl)-C-[(1S)-7,7-dimethyl-2-
oxo-bicyclo[2.2.1]hept-1-yl]-methanesulfonamide (4h)
Compound 4h was prepared using a procedure similar to that of 4g. Yield:
66.1%; mp 136–1388C; [a]2D5 ¼ þ16.2(c ¼ 1.1, CHCl3); IR (KBr), n: 3504,
3261, 3061, 3026, 2957, 1744, 1604, 1494, 1454, 1372, 1310, 1143, 1049,
1
964, 754, 703 cm21; H NMR: d 7.43–6.96 (m, 15H), 4.61 (d, J ¼ 9.6 Hz,
1H), 3.62 (m, 1H), 3.48 (dd, J ¼ 7.2, 14.4 Hz, 4H), 3.28 (d, 1H), 3.04
(d, J ¼ 13.8 Hz, 2H), 2.87 (dd, J ¼ 7.2, 14.4 Hz, 2H), 2.58 (dd, J ¼ 1.8,
11.4 Hz, 2H), 2.27(d, 1H), 2.06–1.79 (m, 2H), 1.46–1.40 (m, 1H), 1.22–
1.19 (m, 1H), 0.84 (s, 3H), 0.64 (s, 3H). Anal. calcd. for C33H39NO4S: C,
72.63%; H, 7.20%; N, 2.57%. Found: C, 72.54%; H, 7.15%; N, 2.61%.
N-(1S)-[1-(2-Methyl)propyl-2-hydroxy-2,2-diphenyl-ethyl]-C-[(1S)-
7,7-dimethyl-2-oxo-bicycle[2.2.1]hept-1-yl]-methanesulfonamide (4i)
Compound 4i was prepared using a procedure similar to that of 4g. Yield:
69.01%; mp 202–2048C; [a]2D5 ¼ þ9.30 (c ¼ 0.978, CHCl3); IR (KBr), n:
3447, 3373, 2957, 1723, 1449, 1326, 1143, 1071, 1020, 990, 804, 748,
1
701 cm21; H NMR: d 7.60 (d, J ¼ 8.1 Hz, 2H), 7.44 (d, J ¼ 7.5 Hz, 2H),
7.26–7.06 (m, 6H), 5.05 (d, J ¼ 9 Hz, 1H), 4.84–4.77 (m, 1H), 3.19
(s, 1H), 2.25–1.76 (m, 6H), 1.53 (s, 2H), 1.43–1.06 (m, 4H), 0.98
(d, J ¼ 5.7 Hz, 3H), 0.79 (d, J ¼ 6.6 Hz, 3H), 0.75 (s, 3H), 0.45 (s, 3H).
Anal. calcd. for C28H37NO4S: C, 69.52%; H, 7.72%; N, 2.90%. Found: C,
69.59%; H, 7.75%; N, 2.83%.
N-(1S)-[1-(2-Methyl)propyl-2-hydroxy-2,2-dibenzyl-ethyl]-C-[(1S)-
7,7-dimethyl-2-oxo-bicycle[2.2.1]hept-1-yl]-methanesulfonamide (4j)
Compound 4j was prepared using a procedure similar to that of as 4g. Yield:
52.18%; mp 149–1518C; [a]2D5 ¼ þ51.82 (c ¼ 0.961 CHCl3); IR (KBr), n:
3452, 3353, 3269, 2952, 1732, 1602, 1494, 1452, 1322, 1278, 1136, 1050,
;
1004, 964, 933, 820, 754, 702 cm21 1H NMR: d 7.34–7.21 (m, 10H),
5.24 (d, J ¼ 9 Hz, 1H), 3.77 (d, J ¼ 15.3 Hz, 1H), 3.63–3.56 (dd,
J ¼ 8.7 Hz, 14.1 Hz,1H), 3.01–2.94 (m, 2H), 2.84–2.68 (m, 3H), 2.57