1618
K. Nakata et al. / Tetrahedron: Asymmetry 22 (2011) 1610–1619
128.76, 128.54, 128.51, 128.4, 128.3, 128.2, 127.3, 127.1, 77.1, 66.8,
56.9, 39.5, 28.8, 27.3, 25.9, 25.8, 25.7; HR-MS: calcd for C29H30O4Na
(M+Na+) 465.2036, found 465.2031.
8.0, 5.0 Hz, 1H, 4-H), 2.18 (dddd, J = 14.1, 8.0, 6.0, 4.0 Hz, 1H, 3-
H), 2.08 (dddd, J = 14.1, 9.0, 5.0, 4.5 Hz, 1H, 3-H), 0.93 (s, 9H,
TBS), 0.05 (s, 3H, TBS), 0.03 (s, 3H, TBS); 13C NMR (CDCl3): d
171.8, 170.1, 138.4, 138.2, 135.3, 128.74, 128.71, 128.6, 128.5,
128.4, 128.3, 128.1, 127.3, 127.2, 69.8, 66.9, 58.2, 56.8, 34.0, 25.8,
O
18.2, ꢀ5.5, ꢀ5.6; HR-MS: calcd for
C
31H38O5SiNa (M+Na+)
O
CHPh
Ph
541.2381, found 541.2391.
2
BnO
O
O
(R 2h
O
CHPh
2
BnO
OTBS
O
4.1.20. Benzyl (R)-2-(diphenylacetyloxy)-4-phenylbutanoate
(R)-2h [Table 1, entry 8, 96% ee, s = 140]
(R
2k
Mp: 75.3–76.0 °C (hexane); HPLC (CHIRALPAK AD-H, i-PrOH/
hexane = 1:9, flow rate = 1.0 mL/min): tR = 11.4 min (2.0%),
tR = 12.2 min (98.0%); IR (KBr): 1734, 1496, 1455, 735, 697 cmꢀ1
;
4.1.23. Benzyl (R)-5-(tert-butyldimethylsiloxy)-2-(diphenylace-
tyloxy)pentanoate (R)-2k [Table 1, entry 11, 95% ee, s = 177]
HPLC (CHIRALPAK IC, i-PrOH/hexane = 1:50, flow rate = 1.0 mL/
min): tR = 9.5 min (2.4%), tR = 11.3 min (97.6%); IR (neat): 1601,
1H NMR (CDCl3): d 7.36–7.09 (m, 18H, Ph), 6.93–6.88 (m, 2H, Ph),
5.12 (d, J = 12.0 Hz, 1H, Bn), 5.11 (s, 1H, 20-H), 5.07 (d, J = 12.0 Hz,
1H, Bn), 5.01 (dd, J = 7.0, 6.0 Hz, 1H, 2-H), 2.54–2.42 (m, 2H, 4-H),
2.12–2.05 (m, 2H, 3-H); 13C NMR (CDCl3): d 171.9, 169.7, 140.1,
138.3, 138.2, 135.2, 128.77, 128.77, 128.66, 128.58, 128.48,
128.44, 128.41, 128.38, 128.3, 127.4, 127.3, 126.2, 72.1, 67.1,
56.8, 32.6, 31.0; HR-MS: calcd for C31H28O4Na (M+Na+) 487.1880,
found 487.1903.
1496, 1454, 839, 697 cmꢀ1 1H NMR (CDCl3): d 7.35–7.20 (m,
;
15H, Ph), 5.16 (d, J = 12.0 Hz Hz, 1H, Bn), 5.12 (d, J = 12.0 Hz, 1H,
Bn), 5.11 (s, 1H, 20-H), 5.11 (dd, J = 8.5, 5.0 Hz, 2H, 2-H), 3.51 (t,
J = 6.0 Hz Hz, 2H, 5-H), 1.97–1.81 (m, 2H, 3-H), 1.50–1.41 (m, 2H,
4-H), 0.85 (s, 9H, TBS), –0.02 (s, 6H, TBS); 13C NMR (CDCl3): d
172.0, 169.8, 138.3, 138.2, 135.2, 128.7, 128.7, 128.6, 128.5,
128.4, 128.3, 128.1, 127.3, 127.2, 72.8, 66.9, 62.0, 56.8, 28.1, 27.7,
O
25.9, 18.2, ꢀ5.4; HR-MS: calcd for
C
32H40O5SiNa (M+Na+)
O
CHPh
OTBS
555.2537, found 555.2536.
2
BnO
O
O
(R
2i
O
CHPh2
BnO
OTBS
O
4.1.21. Benzyl (R)-3-(tert-butyldimethylsiloxy)-2-(diphenylace-
tyloxy)propanoate (R)-2i [Table 1, entry 9, 94% ee, s = 77]
HPLC (CHIRALPAK AD-H, i-PrOH/hexane = 1:50, flow rate =
0.5 mL/min): tR = 21.1 min (97.0%), tR = 31.9 min (3.0%); IR (neat):
(R
2l
1743, 1496, 1455, 746, 698 cmꢀ1 1H NMR (CDCl3): d 7.36–7.20
;
4.1.24. Benzyl (R)-14-(tert-butyldimethylsiloxy)-2-(diphenyl-
acetyloxy)tetradecanoate (R)-2l [Table 1, entry 12, 95% ee,
s = 119]
(m, 15H, Ph), 5.23 (dd, J = 5.0, 3.0 Hz, 1H, 2-H), 5.18 (d,
J = 12.0 Hz, 1H, Bn), 5.14 (d, J = 12.0 Hz Hz, 1H, Bn), 5.13 (s, 1H,
20-H), 4.03 (dd, J = 11.5, 5.0 Hz, 1H, 3-H), 3.91 (dd, J = 11.5, 3.0 Hz,
1H, 3-H), 0.80 (s, 9H, TBS), ꢀ0.05 (s, 3H, TBS), ꢀ0.06 (s, 3H, TBS);
13C NMR (CDCl3): d 172.0, 167.8, 138.3, 138.1, 135.2, 128.8,
128.7, 128.6, 128.53, 128.46, 128.3, 128.2, 127.3, 127.2, 74.4,
67.1, 62.6, 56.8, 25.6, 18.1, ꢀ5.58, ꢀ5.58; HR-MS: calcd for
HPLC (CHIRALPAK AD-H, i-PrOH/hexane = 1:100, flow
rate = 1.0 mL/min): tR = 13.6 min (2.6%), tR = 19.5 min (97.4%); IR
(neat): 1745, 1496, 1457, 837, 699 cmꢀ1 1H NMR (CDCl3): d
;
7.24–7.09 (m, 15H, Ph), 5.05 (d, J = 12.3 Hz, 1H, Bn), 5.01 (d,
J = 12.3 Hz, 1H, Bn), 5.00 (s, 1H, 20-H), 4.97 (t, J = 6.5 Hz, 1H,
2-H), 3.49 (t, J = 6.5 Hz, 2H, 14-H), 1.69 (td, J = 7.0, 6.5 Hz Hz, 2H,
3-H), 1.40 (tt, J = 7.3, 6.5 Hz, 2H, 13-H), 1.24–0.09 (m, 18H,
4-H, 5-H, 6-H, 7-H, 8-H, 9-H, 10-H, 11-H, 12-H), 0.78 (s, 9H, TBS),
ꢀ0.07 (s, 6H, TBS); 13C NMR (CDCl3): d 172.1, 170.0, 138.3, 138.2,
135.3, 128.71, 128.70, 128.6, 128.5, 128.4, 128.3, 128.2, 127.3,
127.2, 72.9, 66.9, 63.3, 56.8, 32.9, 31.0, 29.62, 29.56, 29.56, 29.43,
29.39, 29.26, 28.9, 26.0, 25.8, 24.9, 18.4, ꢀ5.3; HR-MS: calcd for
C
30H36O5SiNa (M+Na+) 527.2224, found 527.2245.
O
O
CHPh
2
BnO
OTBS
O
C
41H58O5SiNa (M+Na+) 681.3946, found 681.3947.
(R
2j
Acknowledgment
4.1.22. Benzyl (R)-4-(tert-butyldimethylsiloxy)-2-(diphenylace-
tyloxy)butanoate (R)-2j [Table 1, entry 10, 93% ee, s = 100]
HPLC (CHIRALPAK AD-H, i-PrOH/hexane = 1:50, flow rate =
1.0 mL/min): tR = 6.3 min (96.6%), tR = 9.6 min (3.4%); IR (neat):
This study was supported by a Research Grant from The Naito
Foundation.
References
1740, 1497, 1455, 747, 699 cmꢀ1 1H NMR (CDCl3): d 7.46–7.31
;
1. Shiina, I.; Nakata, K. Tetrahedron Lett. 2007, 48, 8314.
2. Shiina, I.; Nakata, K.; Sugimoto, M.; Onda, Y.; Iizumi, T.; Ono, K. Heterocycles
2009, 77, 801.
(m, 15H, Ph), 5.36 (dd, J = 9.0, 4.0 Hz, 1H, 2-H), 5.28 (d,
J = 12.3 Hz, 1H, Bn), 5.23 (d, J = 12.3 Hz, 1H, Bn), 5.21 (s, 1H, 20-
H), 3.67 (ddd, J = 10.3, 6.0, 4.5 Hz Hz, 1H, 4-H), 3.60 (ddd, J = 10.3,
3. Nakata, K.; Shiina, I. Heterocycles 2010, 80, 169.