K. Kai et al. / Tetrahedron 64 (2008) 6760–6769
6767
mixture, 69%). 1H NMR (270 MHz, CDCl3)
d
ꢀ0.01–0.07 (6H), 0.82–
t, J¼6.9 Hz), 3.65 (2H, t, J¼5.9 Hz), 3.68 (3H, s). 13C NMR
0.86 (9H), 1.22–1.62 (8H), 2.27 (2H, t, J¼7.6 Hz), 2.49 (0.5H, m),
(67.5 MHz, CDCl3) d
21.0, 32.0, 33.6, 51.5, 62.2, 174.2. MS (FABþ) m/z
2.59–2.62 (0.5H, m), 2.66 (0.5H, m), 2.75–2.89 (0.5H, m), 3.20 (0.5H,
133 [MþH]þ.
m), 3.49–3.55 (0.5H, m). 13C NMR (67.5 MHz, CDCl3)
d
ꢀ5.04, ꢀ4.90,
ꢀ4.40, 18.13, 20.98, 24.50, 24.80, 24.94, 25.62, 25.77, 25.82, 29.12,
29.22, 31.55, 33.95, 34.47, 35.04, 44.80, 44.87, 51.41, 54.58, 55.90,
60.34, 71.25, 74.45, 171.08, 174.11. MS (ESIþ) m/z 317 [MþH]þ.
4.4.2. Methyl 5-oxopentanoate (32)
Reaction procedure as in Section 4.2.2 was followed. Chroma-
tography: hexane–EtOAc (6:4). Colorless oil (64%). 1H NMR
(270 MHz, CDCl3)
d
1.96 (2H, t, J¼7.2 Hz), 2.38 (2H, t, J¼7.2 Hz), 2.54
4.3.7. Methyl 7-[(tert-butyldimethylsilyl)oxy]-8-hydroxyhexadeca-
10,13-diynoate (40)
(2H, t, J¼7.2 Hz), 3.68 (3H, s), 9.78 (1H, br). 13C NMR (67.5 MHz,
CDCl3)
d
17.3, 32.9, 42.9, 51.6, 173.3, 201.4. MS (FABþ) m/z 131
1,4-Heptadiyne (14) was freshly prepared from ethylmagnesium
bromide and propargyl bromide in the presence of copper(I) chlo-
ride as reported previously.7 Synthesis of 40 was conducted by using
14 instead of 13. Reactionprocedure as in Section 4.2.6 was followed.
Chromatography: hexane–EtOAc(85:15). Orangeoil(diastereomeric
[MþH]þ.
4.4.3. Methyl 5-hydroxyhept-6-enoate (33)
Reaction procedure as in Section 4.2.3 was followed. Chroma-
tography: hexane–EtOAc (6:4). Orange oil (30%). 1H NMR (270 MHz,
mixture, 58%).1H NMR (270 MHz, CDCl3)
d
0.07–0.10 (6H), 0.88 (9H),
CDCl3)
d
1.52–1.77 (4H), 2.36 (2H, t, J¼7.2 Hz), 3.67 (3H, s), 4.12 (1H,
1.11 (3H, t, J¼7.5 Hz), 1.28–1.65 (8H), 2.12–2.20 (2H), 2.27–2.40 (4H),
m), 5.14 (1H, d, J¼11.5 Hz), 5.24 (1H, d, J¼15.8 Hz), 5.86 (1H, m). 13
C
3.11 (2H, m), 3.60–3.78 (2H), 3.66 (3H, s).13C NMR (67.5 MHz, CDCl3)
NMR (67.5 MHz, CDCl3) d 20.7, 33.8, 36.2, 51.5, 72.7, 114.9, 140.8,
d
ꢀ4.71, ꢀ4.53, ꢀ4.47, ꢀ4.25, 9.70, 9.74, 12.33, 13.85, 13.87, 14.17,
174.0. MS (FABþ) m/z 159 [MþH]þ.
18.05, 22.68, 24.45, 24.57, 24.85, 24.88, 25.85, 29.24, 29.35, 31.40,
33.57, 33.97, 34.01, 51.47, 71.10, 72.40, 72.67, 73.36, 73.44, 73.84,
76.74, 76.79, 77.21, 81.91. 82.00, 174.16, 174.21. HRMS (ESIþ) m/z
431.2636 [MþNa]þ (calcd for C23H40NaO4Si, 431.2594).
4.4.4. Methyl 5-hydroxy-5-(oxiran-2-yl)pentanoate (34)
Reaction procedure as in Section 4.2.4 was followed. Chroma-
tography: hexane–EtOAc (5:5). Colorless oil (diastereomeric mix-
ture, 41%). 1H NMR (270 MHz, CDCl3)
d
1.57–1.88 (4H), 2.38 (2H, m),
2.71–2.76 (1H), 2.80–2.84 (1H), 2.97–3.03 (1H), 3.46 (0.5H, m), 3.84
(0.5H, m). 13C NMR (67.5 MHz, CDCl3)
20.68, 20.73, 32.66, 33.64,
4.3.8. (10Z,13Z)-Methyl 7-[(tert-butyldimethylsilyl)oxy]-8-hydroxy-
hexadeca-10,13-dienoate (41)
d
Reaction procedure as in Section 4.2.7 was followed. Orange oil
33.71, 33.76, 43.45, 45.06, 51.56, 54.32, 55.19, 68.12, 71.16, 173.94.
(diastereomeric mixture, quantitatively). 1H NMR (270 MHz, CDCl3)
d
MS (FABþ) m/z 175 [MþH]þ.
0.07–0.09 (6H), 0.91 (9H), 0.97 (3H, t, J¼7.3 Hz), 1.21–1.75 (6H),
2.04–2.35 (6H), 2.73–2.95 (2H), 3.45–3.74 (1H), 3.67 (3H, s), 5.26–
5.54 (4H). 13C NMR (67.5 MHz, CDCl3)
4.4.5. Methyl 5-[(tert-butyldimethylsilyl)oxy]-5-(oxiran-2-yl)-
pentanoate (17)
Reaction procedure as in Section 4.2.5 was followed. Chroma-
tography: hexane–EtOAc (95:5). Colorless oil (diastereomeric
d
ꢀ4.60, ꢀ4.42, ꢀ4.10, 13.96,
14.21, 18.08, 20.43, 20.57, 24.90, 25.19, 25.68, 25.87, 51.42, 72.65,
74.17, 74.48, 74.83, 125.28, 125.64, 125.84, 126.85, 129.02, 130.48,
130.88, 132.15, 174.11, 174.15. HRMS (ESIþ) m/z 435.2910 [MþNa]þ
(calcd for C23H44NaO4Si, 435.2907).
mixture, 46%). 1H NMR (270 MHz, CDCl3)
d
ꢀ0.04–0.11 (6H), 0.87–
0.90 (9H),1.50–1.86 (4H), 2.30–2.36 (2H), 2.64 (0.5H, m), 2.70 (0.5H,
m), 2.77 (0.5H, t-like), 2.84–2.94 (1H), 3.27 (0.5H, m), 3.57 (0.5H,
4.3.9. (10Z,13Z)-Methyl 7-[(tert-butyldimethylsilyl)oxy]-8-
oxohexadeca-10,13-dienoate (42)
m), 3.66 (3H, s). 13C NMR (67.5 MHz, CDCl3)
d
ꢀ5.06, ꢀ4.91, ꢀ4.38,
18.13, 20.37, 20.78, 25.63, 25.78, 25.83, 33.92, 34.06, 34.56, 44.78,
44.88, 51.49, 54.40, 55.75, 70.95, 74.24, 173.81. HRMS (ESIþ) m/z
311.1653 [MþNa]þ (calcd for C14H28NaO4Si, 311.1654).
Reaction procedure as in Section 4.2.8 was followed. Chroma-
tography: hexane–EtOAc (95:5). Orange oil (41%). 1H NMR
(270 MHz, CDCl3) d 0.05 (3H, s), 0.06 (3H, s), 0.93 (9H, s), 0.97 (3H, t,
J¼7.5 Hz), 1.20–1.40 (4H), 1.50–1.70 (4H), 2.06 (2H, m), 2.29 (2H,
t, J¼7.5 Hz), 2.75 (2H, t, J¼5.6 Hz), 3.35 (2H, m), 3.66 (3H, s), 4.05 (1H,
t, J¼5.9 Hz), 5.24–5.45 (2H), 5.52–5.63 (2H). 13C NMR (67.5 MHz,
4.4.6. Methyl 5-[(tert-butyldimethylsilyl)oxy]-6-hydroxytetradeca-
8,11-diynoate (44)
Reaction procedure as in Section 4.2.6 was followed. Chroma-
tography: hexane–EtOAc (9:1). Orange oil (diastereomeric mixture,
CDCl3)
d
ꢀ4.9, 14.2, 18.1, 20.6, 24.5, 24.7, 25.7 (Cꢂ3), 25.8, 29.0, 33.9,
34.8, 36.0, 51.4, 78.6, 121.0, 126.4, 131.5, 132.4, 174.1, 211.6. HRMS
78%). 1H NMR (270 MHz, CDCl3)
d 0.08–0.11 (6H), 0.89 (9H),
(ESIþ) m/z 433.2750 [MþNa]þ (calcd for C23H42NaO4Si, 433.2750).
1.11 (3H, t, J¼7.2 Hz), 1.40–1.80 (4H), 2.12–2.41 (6H), 3.11–3.13
(2H), 3.55–3.81 (2H), 3.66 (3H, s). 13C NMR (67.5 MHz, CDCl3)
4.3.10. (10Z,13Z)-7-Hydroxy-8-oxohexadeca-10,13-dienoate (5)
Reaction procedure as in Sections 4.2.9, 4.2.10 was followed.
Chromatography: hexane–EtOAc (6:4), HPLC [CAPCELL PAK UG120
20ꢂ250 mm, 60% C/(BþC), 10 mL/min]. White solid (66%, 2 steps).
d
ꢀ4.71, ꢀ4.56, ꢀ4.48, ꢀ4.30, 9.71, 9.75, 12.38, 13.86, 14.19, 18.05,
21.47, 22.85, 24.38, 25.86, 31.127, 33.17, 33.99, 34.12, 51.51,
71.16, 72.25, 72.41, 73.35, 73.55, 76.00, 76.41, 81.95, 82.03, 173.76.
HRMS (ESIþ) m/z 403.2279 [MþNa]þ (calcd for C21H36NaO4Si,
403.2281).
1H NMR (270 MHz, CDCl3)
d
0.98 (3H, t, J¼7.6 Hz), 1.20–1.75 (7H),
1.84 (1H, m), 2.06 (2H, m), 2.37 (2H, t, J¼7.3 Hz), 2.78 (2H, t,
J¼7.0 Hz), 3.28 (2H, t-like), 4.27 (1H, m), 5.29 (1H, m), 5.42 (1H, m),
4.4.7. (8Z,11Z)-Methyl 5-[(tert-butyldimethylsilyl)oxy]-6-
hydroxytetradeca-8,11-dienoate (45)
5.54 (1H, m), 5.63 (1H, m). 13C NMR (67.5 MHz, CDCl3)
d 14.2, 20.6,
24.4, 24.5, 25.8, 28.7, 33.3, 33.7, 36.7, 76.0, 119.9, 125.9, 132.7, 132.8,
Reaction procedure as in Section 4.2.7 was followed. Chroma-
tography: hexane–EtOAc (9:1). Orange oil (diastereomeric mixture,
179.1, 210.1. HRMS (ESIþ) m/z 305.1730 [MþNa]þ (calcd for
C
16H26NaO4, 305.1729).
81%). 1H NMR (270 MHz, CDCl3)
d 0.08–0.09 (6H), 0.90 (9H), 0.97
(3H, t, J¼7.2 Hz), 1.23–1.70 (5H), 1.90–2.34 (5H), 2.72–2.84 (2H, m),
4.4. Synthesis of (8Z,11Z)-5-hydroxy-6-oxotetradeca-8,11-
3.39–3.70 (2H), 3.66 (3H, s), 5.25–5.56 (4H). 13C NMR (67.5 MHz,
dienoate (6)
CDCl3)
d
ꢀ4.61, ꢀ4.47, ꢀ4.17, 14.04, 14.18, 14.22, 18.08, 20.57, 20.62,
25.52, 25.68, 25.86, 29.27, 29.30, 31.52, 31.75, 33.94, 34.12, 51.49,
72.67, 74.12, 74.47, 74.91, 125.49, 125.70, 126.82, 126.89, 130.60,
131.00, 132.17, 132.56, 173.79, 173.92. HRMS (ESIþ) m/z 407.2594
[MþNa]þ (calcd for C21H40NaO4Si, 407.2594).
4.4.1. Methyl 5-hydroxypentanoate (31)
Reaction procedure as in Section 4.2.1 was followed. Colorless
oil (98%). 1H NMR (270 MHz, CDCl3)
d 1.54–1.78 (5H), 2.36 (2H,