2842 Devkate et al.
Asian J. Chem.
OH
of attention has been given on developing Gilman reagents,
which are potentially valuable species obtained from organo-
lithium reagents that remains to be investigated [23]. The
reactivity of cuprate chemistry is sometimes sacrificed to some
extent relative to its analogue homocuprates R2CuLi [24-26],
throughout the study of the course of reaction of the most
strongest higher order cynocuprates. The aryl substituted cyclo-
alkenes are formed from cycloalkanones by the nucleophilic
addition of an aryl or alkyl Grignard reagents followed by
removal of water molecule. The resulting alkenes formed by
this strategies are important reactants for asymmetric epoxida-
tion process [27-30]. For the preparation of the chiral secondary
alcohols by the enantioselective and regioselective addition
of organozinc reagents like alkylzinc to the aldehyde is conve-
nient and most practical method [31-33] that is usually utilized
in the organometallic chemistry. Moreover, the Grignard reagents
acts a nucleophiles in ring opening of chiral epoxides and it is
one of the most effective and economical protocol for the
synthesis of optically active alcohols with high enantiomeric
purity [34].
O
i) R2MgBr, THF, Li2MnCl , N2
O
4
O
ii) HCl
R1
R2
R1
R1: H, -Cl, -NO , -Cl, -NO
R2: Ph, PhCH -
2
p
p
o
o
2
2
1
2
Scheme-I: Addition of Grignard reagent to epoxides
1-Phenoxy-3-phenylpropan-2-ol (2a): Liquid, m.f.:
1
C15H16O2, IR (KBr, νmax, cm–1): 2970, 1600, 1110, 3600, H
NMR (500 MHz, CDCl3), δ ppm, 6.90 (m, J = 8, 2.5 & 1 Hz,
2H), 7.2 (m, J = 8, 2.5 & 1 Hz, 2H), 6.93 (m, J = 8, 2.5 & 1
Hz, 1H), 7.15 (m, J = 7.5, 2.0 & 1 Hz, 2H), 7.22 (m, J = 7, 2
& 1 Hz, 2H), 7.1 (m, J = 7, 2 & 1 Hz, 1H), 4.1 (d, J = 7 Hz,
2H), 4.35 (m, J = 7 Hz, 1H), 2.8 (d, J = 7 Hz, 2H), 1.60 (s,
1H), 13C NMR (125 MHz, CDCl3), δ ppm, 158.5, 115, 129,
121.2, 72.9, 70.2, 42.5, 138.8, 130.1, 129.2, 127.
1-(4-Chlorophenoxy)-3-phenylpropan-2-ol (2b): Yellow
liquid, m.f.: C15H15O2Cl, IR (KBr, νmax, cm–1): 2974, 1610,
1100, 3600, 650, 1H NMR, (500 MHz, CDCl3), δ ppm, 6.80
(d, J = 7.5 Hz, 2H), 7.25 (d, J = 7.5 Hz, 2H), 7.12 (m, J = 8,
2.5 & 1 Hz, 2 H), 7.22 (m, J = 8, 2.5 & 1 Hz, 2 H), 7.17 (m, J
= 8, 2.5 & 1 Hz, 1H), 3.92 (d, J = 7 Hz, 2H), 4.35 (m, J = 7.0
Hz, 1H), 2.60 (d, J = 7 Hz, 2H), 1.63 (s, 1H), 13C NMR (125
MHz, CDCl3), δ ppm, 157, 115.7, 129.3, 126.5, 138.2, 131.4,
130, 127.6, 72.5, 70.10, 42.8.
1-(4-Nitrophenoxy)-3-phenylpropan-2-ol (2c): Liquid,
m.f.: C15H15NO4, IR (KBr, νmax, cm–1): 2978, 1596, 1110, 3650,
1350, 1H NMR (500 MHz, CDCl3), δ ppm, 7.10 (d, J = 8 Hz,
2H), 7.97 (d, J = 8 Hz, 2 H), 7.05 (m, J = 8, 2.5 & 1 Hz, 2H),
7.18 (m, J = 8, 2.5 & 1 Hz, 2H), 6.95 (m, J = 8, 2.5 & 1 Hz,
1H), 4.10 (d, J = 7 Hz, 2 H), 4.46 (m, J = 7 Hz, 1H), 2.85 (d,
J = 7 Hz, 2 H), 1.20 (S, 1H). 13C NMR (125 MHz, CDCl3),
δ ppm, 164.40, 114.9, 127.3, 142.1, 138, 130.2, 129.7, 127.5,
73, 71.3, 43.2.
1-(2-Chlorophenoxy)-3-phenylpropan-2-ol (2d): Pale
yellow liquid, m.f.: C15H15O2Cl, IR (KBr, νmax, cm–1): 2970,
1590, 1110, 3600, 640, 1H NMR (500 MHz, CDCl3), δ ppm,
7.22 (m, J = 8, 2.5 & 1.5 Hz, 1H), 6.80 (m, J = 8 & 2.5 Hz,
1H), 7.01 (m, J = 8 & 2.5 Hz, 1H), 6.65 (m, J = 8, 2.5 & 1.5
Hz, 1H), 7.17 (m, J = 8, 2.5 & 1 Hz, 2H), 7.24 (m, J = 8, 2.5
& 1 Hz, 2H), 7.16 (m, J = 8 & 2.5 Hz, 1H), 4.27 (d, J = 7 Hz,
2H), 4.46 (m, J = 7 Hz, 1H), 2.85 (d, J = 7.0 Hz, 2H), 1.47 (S,
1H), 13C NMR (125 MHz, CDCl3), δ ppm, 155.32, 124.8,
130.9, 123.7, 128.4, 116.7, 73.1, 70.3, 42.6, 138, 130.12, 129,
127.
1-(2-Nitrophenoxy)-3-phenylpropan-2-ol (2e): Yellow
liquid, m.f.: C15H15NO4, IR (KBr, νmax, cm–1): 2900, 1620, 1100,
3600, 1350, 1H NMR (500 MHz, CDCl3), 7.98 (m, J = 8, 2.5
& 1.5 Hz, 1 H), 7.16 (m, J = 8 & 2.5 Hz, 1H), 7.5 (m, J = 8 &
2.5 Hz, 1H), 7.08 (m, J = 8, 2.5 & 1.5 Hz, 1H), 7.14 (m, J = 8,
2.5 & 1.5 Hz, 2H), 7.21 (m, J = 8, 2.5 & 1.5 Hz, 2H), 7.11 (m,
J = 8 & 2.5 Hz, 1H), 4.01 (d, J = 7 Hz, 2H), 4.43 (m, J = 7 Hz,
1H), 2.60 (d, J = 7 Hz, 2H), 1.52 (S, 1H), 13C NMR (125
MHz, CDCl3), δ ppm, 155.5, 137.3, 127.96, 121.7, 135, 118,
138.9, 130.6, 129.7, 127.3, 73.6, 70.4, 42.3
EXPERIMENTAL
The boiling points were determined are uncorrected. IR
spectra were determined on a Shimadzu Miracle 10 ATR
instrument. 1H NMR spectra were recorded on a Bruker 500
MHz spectrometer with CDCl3 as a solvent and TMS as the
internal standard. 13C NMR spectra were recorded on Brucker
125 MHz spectrometer with CDCl3 as the solvent. Column
chromatography was conducted on silica gel 60 (70-230 mesh).
Thin layer chromatography (TLC) was carried out on alumi-
nium sheets precoated with silica gel.
Preparation of Li2MnCl4 solution: In a 500 mL round
bottom flask were added LiCl (1 M, 21.197 g) and MnCl2
(1 M, 31.4610 g) and dried under vaccum at 250 °C for about
2 h and the mixture were allowed to cool at room temperature
followed by addition of 250 mL dry THF. The resulting solution
kept under stirring overnight at room temperature resulting
homogeneous solution of Li2MnCl4.
Preparation of Grignard reagent: In a 500 mL three
necked round bottom flask previously dried with heating gun
and flushed with nitrogen gas were added magnesium turnings
(6.07 g) and diethyl ether (250 mL), to which added iodine to
initiate the reaction followed by addition of aryl bromide
(39.2520 g) drop-wise through septum. After the complete
addition of aryl halide the mixture were stirred at room tempe-
rature for about 1 h to get homogenious 1 M solution of Grignard
reagent.
Addition of Grignard reagent to epoxide: In a 100 mL
three necked round bottom flask were added epoxide (10
mmol) and charged dry THF (25 mL), Li2MnCl4 solution (10
mmol) followed by dropwise addition of Grinard reagent (11
mmol) at room temperature, after complete addition of
Grignard reagent the progress of the reaction were studied by
thin layer chromatography (TLC) and reaction were quenched
with dil. HCl and stirred for 15 min. The product were extracted
with diethylether (10 mL × 3) and dried over anhydrous sodium
sulphate (Scheme-I).
1-Phenoxy-4-phenylbutan-2-ol (2f): Liquid, m.f.:
C16H18O2 IR (KBr, νmax, cm–1): 2972, 1600, 1110, 3650, 1H
NMR (500 MHz, CDCl3), δ ppm, 6.8 (m, J = 8, 2.5 & 1 Hz,