104
D.S. Matteson, D. Fernando / Journal of Organometallic Chemistry 680 (2003) 100Á105
/
trated on a rotary evaporator, leaving a white solid
residue of 7, 22.55 g (96%); 300-MHz 1H-NMR (CDCl3)
added and the solid dissolved. The mixture was allowed
to warm up to 20Á25 8C and kept for 16 h, then worked
/
d 4.38 (dd, Jꢃ
/
6.9 Hz, 1H), 2.36 (m, 1H), 2.26 (m, 1H),
up in the usual manner [7]. Evaporation of the solvent in
a rotary evaporator yielded 9 of sufficient purity for use
in the next step (2.92 g, 99%); 300-MHz 1H-NMR
2.11 (t, Jꢃ6.0 Hz, 1H), 1.92 (m, 1H), 1.87 (m, 1H), 1.80
/
(s, 6H), 1.41 (s, 3H), 1.30 (s, 3H), 1.26 (d, 1H), 0.85 (s,
3H); 75-MHz 13C-NMR (CDCl3) d 86.5, 78.5, 51.4,
(CDCl3) d 4.34 (dd, Jꢃ
(s, 2H), 2.48ꢁ2.23 (m, 2H), 2.11 (t, Jꢃ
1.98ꢁ1.84 (m, 2H), 1.42 (s, 3H), 1.30 (s, 3H), 1.25 (d,
Jꢃ9.3 Hz, 6H), 1.15 (d, Jꢃ9.9 Hz, 1H), 0.85 (s, 3H);
/8.7 Hz, 1H), 3.42 (s, 1H), 2.60
39.3, 38.4, 35.5, 30.7, 30.5, 28.445, 27.1, 26.4, 24.1, C Ã
not detected. HRMS: Calc. for C13H22BBrO2 [Mꢀ
CH3], 285.0661; Found (EI), 285.0658.
/B
/
/6 Hz, 1H),
/
ꢁ
/
/
/
300-MHz 13C-NMR (CDCl3) d 118.2, 86.9, 78.5, 51.1,
39.4, 38.3, 36.8, 35.3, 28.5, 28.2, 27.0, 26.5, 25.5, 24.3,
24.1. HRMS: Calc. for C16H25BClNO2 [Mꢀ], 309.1667;
Found, 309.1686.
4.10. (S)-Pinanediol [(1,1-dimethyl-2-
cyano)ethyl]boronate (8)
4.10.1. Method A: from 2-(2-cyano-1,1-dimethylethyl)-
4,4,5,5-tetramethyl-1,3,2-dioxaborolane (5a) and (S)-
pinanediol
4.12. (S)-Pinanediol (3-cyano-2,2-
dimethylcyclopropyl)boronate (10)
(S)-Pinanediol (1.63 g, 9.56 mmol), 5a (2 g, 9.56
mmol), diethyl ether (50 ml), and water (0.5 ml) were
stirred together for 16 h at 20Á25 8C under argon. The
ether phase was extracted with saturated aqueous
ammonium chloride (50 ml) and the aqueous phase
/
A solution of LDA (10.55 mmol) freshly prepared
from butyllithium and diisopropylamine in THF (7 ml)
was added dropwise to a solution of (S)-pinanediol
(1S)-(1-chloro-3-cyano-2,2-dimethylpropyl)boronate (9)
was extracted with ether (3ꢂ50 ml). The combined
/
organic phase was dried over magnesium sulfate and
concentrated on a rotary evaporator. The residue (3.6 g)
(2.92 g, 10 mmol) in THF (10 ml) at ꢁ
argon. The reaction mixture was kept at 20Á
/
78 8C under
25 8C for 16
/
was chromatographed on silica with 1:9 ethyl acetateÁ
hexane to yield 8, 2.19 g (88%); m.p. 57Á58 8C; 300-
8.7 Hz, 1H),
2.19 (m, 3H), 2.05 (t, Jꢃ5.1
Hz, 1H), 1.91 (m, 1H), 1.38 (s, 3H), 1.29 (s, 3H), 1.13 (s,
6H), 1.06 (d, Jꢃ10.8 Hz, 1H), 0.84 (s, 3H); 75-MHz
13C-NMR (CDCl3) d 118.8, 86.3, 78.3, 51.2, 39.4, 38.2,
B not
/
h. The solution was concentrated on a rotary evapora-
tor. The residue was worked up with diethyl ether (100
ml) and saturated aqueous ammonium chloride (100
ml), and the aqueous phase was extracted with diethyl
/
1
MHz H-NMR (CDCl3) d 4.30 (dd, Jꢃ
/
2.33ꢀ2.34 (AB, 2H), 2.39ꢁ
/
/
/
ether (3ꢂ50 ml). The combined organic phase was
/
/
dried over magnesium sulfate. Concentration under
vacuum yielded a residue of both diastereomers of 10
(2.60 g, 94.9%) in a ratio of 2:1, with the isomer believed
to have the boronic ester group trans to the nitrile
predominating. The isomers were separable by chroma-
tography.
35.5, 28.6, 28.1, 27.1, 26.5, 24.3, 24.2, 24.0, C Ã
/
detected. HRMS: Calc. for C15H24BNO2 [Mꢀ],
261.1900; Found, 261.1899. Anal. Calc. for
C15H24BNO2: C, 68.98; H, 9.26; B, 4.14; N, 5.36; O,
12.25. Found: C, 68.88; H, 9.10; B, 3.45; N, 5.29%.
The product assigned the trans configuration (10a) is
1
a solid, m.p. 72Á
4.29 (dd, Jꢃ8.8 Hz, Jꢃ
(t, Jꢃ5.2 Hz, 1H), 1.92 (m, 1H), 1.79 (dt, Jꢃ
Jꢃ2.2 Hz, 1H), 1.49 (d, Jꢃ6.3 Hz, 1H), 1.38 (d, Jꢃ
Hz, 6H), 1.26 (d, Jꢃ16.5 Hz, 6H), 1.07 (d, Jꢃ11.0 Hz,
1H), 0.83 (s, 3H), 0.51 (d, Jꢃ
6.3 Hz, 1H); 75-MHz 13C-
NMR (CDCl3) d 120.8, 86.4, 78.1, 51.0, 39.4, 38.1, 35.4,
/
74 8C; 300-MHz H-NMR (CDCl3) d
4.10.2. Method B: from (S)-pinanediol (1-bromo-1-
methylethyl)boronate (7)
This synthesis was carried out according to the
procedure described for preparation of 5a but with 7
in place of 4a; yield of chromatographed 8, 50%.
/
/
2.2 Hz, 1H), 2.29 (m, 2H), 2.03
14.6 Hz,
3.0
/
/
/
/
/
/
/
/
4.11. (S)-Pinanediol (1S)-(1-chloro-3-cyano-2,2-
dimethylpropyl)boronate (9)
28.6, 27.0, 26.6, 25.8, 24.5, 24.0, 22.0, 15.2, C Ã
/
B not
detected. HRMS: Calc. for C16H24BNO2 [Mꢀ],
273.1900; Found, 273.1900.
The other product was assigned the cis configuration
(Dichloromethyl)lithium was prepared according to
the usual procedure by addition of butyllithium (12.0
mmol) dropwise down the wall of the flask to a stirred
solution of dichloromethane (1.24 ml, 19 mmol) in THF
1
(10b); 300-MHz H-NMR (CDCl3) d 4.35 (dd, Jꢃ
/
8.8
5.2 Hz,
2.0 Hz,
7.1 Hz, Jꢃ
19.5 Hz, 6H), 1.16 (d, Jꢃ11.0
Hz, Jꢃ
1H), 1.92 (m, 1H), 1.86 (dt, Jꢃ
1H), 1.48 (d, Jꢃ9.6 Hz, 1H), 1.40 (dd, Jꢃ
2.8 Hz, 6H), 1.26 (d, Jꢃ
/
2.2 Hz, 1H), 2.30 (m, 2H), 2.08 (t, Jꢃ
/
/
16.5 Hz, Jꢃ
/
at ꢁ
lethyl)boronate (8) (2.5 g, 9.57 mmol) in THF (10 ml)
was added dropwise. After stirring for 5Á10 min a white
solid formed. The mixture was allowed to warm to
78 8C and stirred for 1 h. Anhydrous zinc chloride
solution (24 ml, 1.0 M in diethyl ether, 24 mmol) was
/
100 8C [12]. (S)-Pinanediol (2-cyano-1,1-dimethy-
/
/
/
/
/
/
Hz, 1H), 0.84 (s, 3H), 0.46 (d, Jꢃ9.6 Hz, 1H); 75-MHz
/
ꢁ
/
13C-NMR (CDCl3) d 119.6, 86.1, 78.0, 51.0, 39.5, 38.1,
35.5, 28.6, 27.6, 27.1, 26.6, 25.1, 24.1, 19.5, 15.4.