316
W.C. Hiscox, D.S. Matteson / Journal of Organometallic Chemistry 614–615 (2000) 314–317
stirred at −100°C [5a]. A solution of 2 (42.2 g, 116
mmol) in tetrahydrofuran (300 ml) was added. The
mixture was allowed to warm to −78°C. Anhydrous
zinc chloride in diethyl ether (208 ml, 1 M) was added
and the solution was kept for 20 h at 20–25°C, then
poured into pentane (1 l). The organic phase was
washed with water (4×200 ml) and concentrated under
vacuum. The residue was dissolved in pentane (400 ml),
washed with water (3×200 ml), dried over magnesium
sulfate, filtered, and concentrated to yield 3 (38.0 g,
79%); 300 MHz 1H-NMR (CDCl3) l 0.85–1.85 (m, 22),
1.42 (s, 9), 1.98–2.25 (m, 2), 2.30–2.52 (m, 2), 3.49 (m,
1), 3.92 (m, 2).
1.7. [(R)-5-(1-Decynyl)dihydro-2(3H)-furanone (6)
(R)-[1,1-Dimethylethyl 4-hydroxy-5-tetradecynoate]
(5) (4.50 g, 1.52 mmol) and p-toluenesulfonic acid
(0.061 g, 0.03 mmol) were dissolved in dichloromethane
(5 ml). When the solution became homogeneous, the
solvent was distilled and the resulting red liquid was
heated at 100°C under vacuum for 2 h. The product
was distilled bulb-to-bulb (130°C, 1 torr), 2.36 g (69%).
The material was chromatographed on silica gel, (20%
1
ethyl acetate in pentane); 300 MHz H-NMR (CDCl3)
l 0.79–0.85 (t, 3), 1.16–1.34 (m, 10), 1.40–1.48 (m, 2),
2.14–2.25 (m, 3), 2.40–2.49 (m, 2), 2.54–2.64 (m, 1),
5.07 (m, 1); 75 MHz 13C-NMR (CDCl3) l 14.0, 18.6,
22.6, 27.9, 28.2, 28.7, 29.0, 29.1, 30.1, 31.7, 69.7, 76.4,
88.7, 176.3.
1.5. [2(1%R),4R,5R]-2-[3-[[(1,1-Dimethylethyl)-
oxy]carbonyl]-1-(1-decynyl)propyl]-4,5-
dicyclohexyl-1,3,2-dioxaborolane (4)
1.8. [R-(Z)]-5-(1-Decenyl)dihydro-2(3H)-furanone (7)
Lithium diisopropylamide (68 ml, 1.5 M, 102 mmol)
was added dropwise to a stirred solution of 1-decyne
(15.3 g, 111 mmol) in THF (250 ml) at −78°C. After
an additional 15 min at −78°C, the resulting solution
of 1-lithiodecyne was transferred via cannula to a
stirred solution of chloro boronic ester 3 (38.0 g, 92.0
mmol) in THF (250 ml). The mixture was allowed to
warm to 20–25°C and stirred for 18 h. Pentane (500
ml) was added. The organic phase was washed with
water (3×250 ml), dried over magnesium sulfate, and
concentrated under vacuum (1 torr) to yield a residue
Hydrogenation of lactone 6 (0.860 g) was carried out
at 1 atm for 1 h at 0°C over Lindlar catalyst (5%
palladium on calcium carbonate poisoned with lead
acetate, 200 mg, plus quinoline, 8 drops) in pentane (50
ml) according to the procedure of Senda and Mori [8];
yield of 7 0.854 g; after chromatography on silica (10%
ethyl acetate in pentane) 0.554 g (65%); 300 MHz
1H-NMR (CDCl3) l 0.83 (t, 3), 1.19–1.31 (m, 10),
1.32–1.42 (m, 2), 1.88–2.00 (m, 1), 2.00–2.17 (m, 2),
2.30–2.40 (m, 1), 2.48–2.60 (m, 2), 5.19–5.27 (m, 1),
5.39–5.47 (m, 1), 5.60–5.69 (m, 1); 75 MHz 13C-NMR
(CDCl3) l 14.1, 22.6, 27.8, 29.0, 29.1, 29.2, 29.3, 29.36,
29.37, 31.8, 76.4, 127.1, 135.8, 177.2; [h]2D4 −71.4°
(c=1.00, CHCl3) [lit. [h]2D5 −70.0° (c=5.0, CHCl3)
[1b], [h]2D1 −70.4° (c=1.082, CHCl3) [8], [h]2D6 −69.93°
(c=9.84, CHCl3) [7], [h]2D6 −71.0° (c=5.387, CHCl3
[9a], [h]2D2 −70.4° (c=0.4, CHCl3) [9b], [h]2D5 −70.0°
(c=6.4, CHCl3) [11], [h]2D5 −70.82° (c=0.19, CHCl3)
[15]; the only value beyond −71°: [h]2D5 −73.9° (c=
1.004, CHCl3) [10b].
1
of 4 (45.8 g, 97%); 300 MHz H-NMR (CDCl3) l 0.86
(t, 3), 0.88–1.91 (m, ꢀ37), 1.42 (s, 9), 2.11 (t, 2),
2.2–2.5 (m, 2), 3.87 (m, 2). This material was used
directly in the next step.
1.6. (R)-[1,1-Dimethylethyl
4-hydroxy-5-tetradecynoate] (5)
Hydrogen peroxide (20 ml, 30%) and sodium hydrox-
ide solution (200 ml, 1 M) were added to a stirred
solution of decynyl boronic ester 4 (45.8 g, 89 mmol) in
diethyl ether (500 ml) in a flask equipped with a reflux
condenser. Stirring at 25°C was continued for 2 h. The
ether phase was separated and concentrated under vac-
uum. The resulting slurry was treated with pentane (500
ml) to complete the precipitation of DICHED, which
was filtered and washed with an additional 250 ml of
pentane. The combined pentane solution was concen-
trated under vacuum to clear, colorless liquid 5 (23.6 g,
89%). A portion was chromatographed on silica with
20% ethyl acetate in pentane; 300 MHz 1H-NMR
(CDCl3) l 0.75 (t, 3), 1.10–1.31 (m, 10), 1.34 (s, 9), 1.37
(t, 2), 1.81 (m, 2), 2.04 (dd, 2), 2.30 (m, 2), 3.11 (br s,
1), 4.30 (m, 1); 75 MHz 13C-NMR (CDCl3) l 13.9, 18.5,
22.3, 27.6, 28.1, 29.0, 29.3, 30.6, 31.2, 32.9, 64.1, 80.2,
80.4, 85.4, 173.0. HRMS: Calc. for C14H23O2 [M–
(55+18)] 223.1698; Found (EI) 223.1683.
Acknowledgements
We thank the National Science Foundation for sup-
port, grant number CHE9613857. Support of the WSU
NMR Center by NIH grant RR 0631401 and NSF
grant CHE-9115282 is also gratefully acknowledged.
References
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