J
O. V. Konstantinova, A. M. Koskinen
Paper
Synthesis
(2E,4E,6R,7S)-7-[(tert-Butyldimethylsilyl)oxy]-3,4,6-trimethylno-
na-2,4-dien-1-ol (38)
1H NMR (400 MHz, CDCl3): δ = 6.74 (ddd, J = 16.7, 10.9, 10.1 Hz, 1 H),
6.18 (d, J = 11.0 Hz, 1 H), 5.68–5.60 (m, 1 H), 5.23 (dd, J = 16.7, 1.8 Hz,
1 H), 5.09 (dd, J = 10.1, 1.9 Hz, 1 H), 3.48 (td, J = 6.1, 3.9 Hz, 1 H), 2.66
(dqd, J = 13.6, 6.8, 3.9 Hz, 1 H), 1.92 (s, 3 H), 1.84 (d, J = 1.1 Hz, 3 H),
1.50–1.33 (m, 2 H), 0.97 (d, J = 6.8 Hz, 3 H), 0.90 (s, 9 H), 0.84 (t, J = 7.4
Hz, 3 H), 0.05 (d, J = 1.0 Hz, 6 H).
13C NMR (101 MHz, CDCl3): δ = 138.79, 135.34, 134.19, 131.25,
125.58, 116.56, 77.40, 37.92, 27.23, 26.07, 18.29, 16.98, 14.41, 14.36,
10.27, –4.09, –4.31.
To a solution of boronic ether 16 (163 mg, 0.81 mmol, 2 equiv) in THF
(1.5 mL) under argon was added TlOEt (0.05 mL, 0.73 mmol, 1.8
equiv) and degassed H2O (0.15 mL) at r.t. and the resulting mixture
was stirred for 5 min. To this mixture were added a solution of iodide
29 (150 mg, 0.41 mmol, 1 equiv) in THF (0.6 mL) and Pd(PPh3)4 (23
mg, 0.02 mmol, 0.05 equiv) and stirring was continued for 4 h. The
mixture was filtered through Celite® and the pad rinsed with Et2O.
The filtrate was concentrated under vacuum and the residue purified
by column chromatography on silica gel (hexane/Et2O, 30:1 to 6:1) to
give adduct 38 (161 mg, 95%) as a colorless oil.
HRMS (ESI): m/z [M + Na]+ calcd for C19H36ONaSi: 331.2433; found:
331.2448.
IR (thin film): 3314, 2957, 2929, 2857, 1462, 1377, 1254, 1102, 1073,
tert-Butyldimethyl{[(3S,4R,5E,7E,9E)-4,6,7-trimethyl-10-(4,4,5,5-
tetramethyl-1,3,2-dioxaborolan-2-yl)deca-5,7,9-trien-3-yl]oxy}si-
lane (45)
1060, 1006, 835, 773 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 5.70 (t, J = 6.3 Hz, 1 H), 5.59 (d, J = 9.5
Hz, 1 H), 4.31 (t, J = 6.0 Hz, 2 H), 3.47 (td, J = 6.1, 3.9 Hz, 1 H), 2.64
(dqd, J = 13.6, 6.8, 3.9 Hz, 1 H), 1.83 (s, 3 H), 1.81 (d, J = 1.1 Hz, 3 H),
1.32–1.50 (m, 2 H), 1.22 (t, J = 5.5 Hz, 1 H), 0.97 (d, J = 6.9 Hz, 3 H),
0.90 (s, 9 H), 0.84 (t, J = 7.4 Hz, 3 H), 0.04 (s, 6 H).
13C NMR (101 MHz, CDCl3): δ = 139.64, 135.02, 130.75, 124.05, 77.36,
60.29, 37.74, 27.24, 26.07, 18.28, 16.98, 14.40, 14.27, 10.27, –4.09,
–4.32.
A mixture of 40 (54 mg, 0.17 mmol, 1 equiv), 4,4,5,5-tetramethyl-2-
vinyl-1,3,2-dioxaborolane (0.059 mL, 0.35 mmol, 2 equiv) and Hovey-
da–Grubbs 1st generation catalyst (16 mg, 0.03 mmol, 0.15 equiv) in
CH2Cl2 (0.7 mL) was heated at 35–40 °C with stirring under argon for
3 h. After completion, the reaction was loaded onto a silica gel column
and eluted with hexane/Et2O (50:1 to 35:1) to give adduct 45 (55 mg,
72%).
HRMS (ESI): m/z [M + Na]+ calcd for C18H36O2NaSi: 335.2382; found:
335.2377.
IR (thin film): 2976, 2958, 2930, 2857, 1606, 1379, 1350, 1257, 1143,
850 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 7.43 (dd, J = 17.3, 11.0 Hz, 1 H), 6.24 (d,
J = 10.9 Hz, 1 H), 5.71 (d, J = 9.0 Hz, 1 H), 5.56 (d, J = 17.3 Hz, 1 H), 3.48
(td, J = 5.9, 4.1 Hz, 1 H), 2.67 (dqd, J = 13.6, 6.8, 4.1 Hz, 1 H), 1.99 (d, J =
0.6 Hz, 3 H), 1.83 (d, J = 1.0 Hz, 3 H), 1.41 (m, 2 H), 1.28 (s, 12 H), 0.97
(d, J = 6.8 Hz, 3 H), 0.89 (s, 9 H), 0.84 (t, J = 7.4 Hz, 3 H), 0.04 (s, 6 H).
13C NMR (101 MHz, CDCl3): δ = 146.75, 142.34, 135.50, 132.72,
127.13, 83.20, 77.32, 38.00, 27.25, 26.06, 24.92, 18.27, 16.92, 14.81,
14.41, 10.16, –4.10, –4.32.
(2E,4E,6R,7S)-7-[(tert-Butyldimethylsilyl)oxy]-3,4,6-trimethylno-
na-2,4-dienal (39)
To a solution of alcohol 38 (96 mg, 0.31 mmol) in CH2Cl2 (15 mL) was
added MnO2 (0.5 g, 6.15 mmol, 20 equiv) portionwise. The reaction
was complete after stirring at r.t. for 1 h. The MnO2 was removed by
filtration through a pad of Celite® and the pad was rinsed with CH2Cl2.
The filtrate was concentrated under reduced pressure and the ob-
tained aldehyde 39 (91 mg, 96%) was used in the next step without
purification.
HRMS (ESI): m/z [M + Na]+ calcd for C25H47O3NaSiB: 457.3285; found:
457.3282.
IR (thin film): 2958, 2930, 2857, 1667, 1462, 1378, 1253, 1154, 1078,
1031, 836, 774 cm–1
.
(2Z,4E,6E,8E,10R,11S)-11-[(tert-Butyldimethylsilyl)oxy]-3,7,8,10-
1H NMR (400 MHz, CDCl3): δ = 10.15 (d, J = 7.9 Hz, 1 H), 6.11 (dd, J =
27.0, 8.4 Hz, 2 H), 3.51 (td, J = 6.0, 3.9 Hz, 1 H), 2.71 (dqd, J = 13.6, 6.8,
3.8 Hz, 1 H), 2.30 (d, J = 0.8 Hz, 3 H), 1.85 (d, J = 1.1 Hz, 3 H), 1.54–1.29
(m, 2 H), 1.00 (d, J = 6.9 Hz, 3 H), 0.89 (s, 9 H), 0.84 (t, J = 7.5 Hz, 3 H),
0.04 (d, J = 3.0 Hz, 6 H).
13C NMR (101 MHz, CDCl3): δ = 192.36, 158.48, 138.31, 135.10,
125.68, 77.11, 37.90, 27.95, 26.02, 18.23, 17.10, 14.43, 14.28, 9.88,
–4.05, –4.39.
tetramethyltrideca-2,4,6,8-tetraenenitrile (41)
To a solution of boronic ether 45 (27 mg, 0.06 mmol, 1 equiv) in THF
(0.9 mL) under argon was added TlOEt (0.01 mL, 0.14 mmol, 2.3
equiv) and degassed H2O (0.09 mL) at r.t. and the mixture stirred for 5
min. Next, a solution of iodide 1 (16 mg, 0.08 mmol, 1.4 equiv) in THF
(1 mL) and Pd(PPh3)4 (7 mg, 0.006 mmol, 0.1 equiv) were added and
stirring was continued for 1 h. The reaction mixture was filtered
through Celite® and the pad was rinsed with Et2O. The filtrate was
concentrated under vacuum. The residue was purified by column
chromatography on silica gel (hexane/Et2O, 100:1 to 80:1) to give ad-
duct 41 (15 mg, 67%) as a colorless oil.
tert-Butyldimethyl{[(3S,4R,5E,7E)-4,6,7-trimethyldeca-5,7,9-
trien-3-yl]oxy}silane (40)
IR (thin film): 2957, 2929, 2856, 2209, 1591, 1378, 1360, 1252, 1078,
To a solution of Ph3PCH3I (250 mg, 0.61 mmol, 2 equiv) in THF (2 mL)
at 0 °C under argon was added NaN(SiMe3)2 (0.55 mL, 1 M in THF, 0.55
mmol, 1.8 equiv). After stirring for 20 min, a solution of aldehyde 39
(91 mg, 0.31 mmol, 1 equiv) in THF (1 mL) was added to the obtained
yellow solution and stirring was continued for 2 h. After the reaction
was complete, it was quenched by the addition of hexane and evapo-
rated under vacuum until dry. The residue was purified by column
chromatography on silica gel (hexane/Et2O, 90:1) to give adduct 40
(76 mg, 84%) as a colorless oil.
1029, 961, 835, 773 cm–1
.
1H NMR (400 MHz, CDCl3): δ = 7.00 (dd, J = 15.0, 11.1 Hz, 1 H), 6.84 (d,
J = 15.0 Hz, 1 H), 6.35 (d, J = 11.1 Hz, 1 H), 5.79 (d, J = 9.5 Hz, 1 H), 5.07
(s, 1 H), 3.50 (td, J = 6.0, 3.9 Hz, 1 H), 2.69 (dqd, J = 13.6, 6.8, 3.9 Hz, 1
H), 2.07 (d, J = 1.3 Hz, 3 H), 2.00 (s, 3 H), 1.87 (d, J = 1.0 Hz, 3 H), 1.33–
1.51 (m, 2 H), 0.99 (d, J = 6.8 Hz, 3 H), 0.90 (s, 9 H), 0.85 (t, J = 7.4 Hz, 3
H), 0.05 (s, 6 H).
13C NMR (101 MHz, CDCl3): δ = 156.82, 144.25, 135.41, 133.96,
133.73, 128.79, 124.49, 117.63, 94.91, 77.32, 38.02, 27.50, 26.06,
19.59, 18.28, 17.09, 14.78, 14.40, 10.13, –4.07, –4.32.
IR (thin film): 2957, 2929, 2857, 1462, 1378, 1252, 1102, 1059, 1005,
833, 772 cm–1
.
Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–L