Stereoselective cyclopropylmethylation reactions of homoallylstannanes with carbon electrophiles

Article abstract of DOI:10.1016/S0040-4020(00)00389-6

The reactions of homoallylstannanes with acetals, aldehydes, and acyl chlorides in the presence of a Lewis acid proceeded smoothly to give the corresponding cyclopropylmethylated products. The reactions of E-3- pentenylstannane with aldehydes were stereos

Full text of DOI:10.1016/S0040-4020(00)00389-6

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 4683±4689
Stereoselective Cyclopropylmethylation Reactions of
Homoallylstannanes with Carbon Electrophiles
*
Masanobu Sugawara and Jun-ichi Yoshida
Department of Synthetic Chemistry & Biological Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku,
Kyoto 606-8501, Japan
Received 21 March 2000; accepted 9 May 2000
AbstractÐThe reactions of homoallylstannanes with acetals, aldehydes, and acyl chlorides in the presence of a Lewis acid proceeded
smoothly to give the corresponding cyclopropylmethylated products. The reactions of E-3-pentenylstannane with aldehydes were stereo-
selective and gave the erythro products predominantly. A mechanism involving antiperiplanar attack is suggested. The stereoselectivity of
the Z isomer was, however, not high. q 2000 Elsevier Science Ltd. All rights reserved.
Introduction
reaction of homoallylstannanes with carbon electrophiles
such as acetals, aldehydes, and acyl halides could be accom-
plished in the presence of a suitable Lewis acid.7 In addition
to a mechanistic interest, synthetic utility of this reaction is
noteworthy. This reaction serves as an ef®cient and con-
venient method for cyclopropylmethylation of carbonyl
compounds. This type of tranformation is rather dif®cult
to accomplish with the homoallyl Grignard reagent because
of a ring-opening side reaction.8 Use of the tin reagent,
however, enables the direct cyclopropylmethylation of
Allylstannanes are useful synthetic reagents for the
construction of carbon±carbon bonds, because they undergo
regio- and stereoselective allylation reactions with carbonyl
compounds in the presence of Lewis acids or under thermal
conditions.1 Moreover, they react with organic halides to
give the corresponding allylated products under radical
conditions.2 The reactions of homoallylstannanes, however,
are less popular in organic synthesis. Peterson and
Robbins3a reported a pioneering work on the reactions of
homoallylstannanes with various heteroatom electrophiles,
such as Cl2, Br2, I2, SO3, HgCl2, RSCl and RSeX, which lead
to the formation of the corresponding cyclopropylmethyl
compounds. A mechanism involving the initial addition of
an electrophile to the carbon±carbon double bond of homo-
allylstannane followed by facile g-elimination of the formal
stannyl cation4 to form the cyclopropane ring seems to be
the most plausible (Scheme 1).
To our knowledge, however, there had been no successful
example of the reaction of homoallylstannanes with carbon
electrophiles to achieve intermolecular carbon±carbon bond
formation.5 In fact, it was reported that the reaction of
homoallylstannane with triphenylmethyl cation led to the
hydride abstraction followed by b-elimination of the stannyl
bromide (Scheme 2).3b Hydride losses at carbon atoms b to
tin are known to occur rapidly and quantitatively.6
Scheme 1.
We have been interested in the reaction of homoallyl-
stannanes with carbon electrophiles and found that the
Keywords: cyclopropylmethylation; homoallylstannane; stereoselective; g-
elimination; g-effect.
* Corresponding author. Tel.: 181-75-753-5651, fax: 181-75-753-5911;
e-mail: yoshida@sbchem.kyoto-u.ac.jp
Scheme 2.
0040±4020/00/$ - see front matter q 2000 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(00)00389-6

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M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
Table 1. Reactions of homoallylstannanes with carbon electrophiles in the presence of Lewis acidsa
a
Reaction conditions: 1.0 equiv. of 1, 1.0±1.3 equiv. of 2 and 1.1 equiv. of TiCl4 in CH2Cl2 (1.8 mL) at 2788C for 3±3.5 h.
TMSOTf (1.1 equiv.) was used instead of TiCl4, at 2408C, 3 h.
Determined by GLC.
The homoallylated product 4 was not fully characterized.
b
c
d
carbonyl compounds and related compounds. In this paper,
we report on full details of this study.
tives, if we choose a suitable precursor and a Lewis acid.
The use of BF3´OEt2 as a Lewis acid caused decrease of the
yield of the product (3a). The use of TiCl4 gave rise to a very
low yield of 3a; presumably the methoxy group in 3a was
eliminated by the action of TiCl4, although the product was
not fully characterized (Scheme 3).
Results and Discussion
The reaction of benzaldehyde dimethyl acetal (1a) with
3-butenyltributylstannane (2a, 1.3 equiv.)9 in the presence
of TMSOTf (1.1 equiv.) in CH2Cl2 at 2408C for 3 h gave
the corresponding cyclopropylmethylated product 3a in
83% yield (Table 1, entry 1). This result indicates that
carbon electrophiles10 are also effective for the reactions
toward homoallylstannanes to form cyclopropane deriva-
Acyl halides and aldehydes were also found to be effective
as carbon electrophiles (Table 1, entries 2±8). The corre-
sponding cyclopropylmethylated products 3 were obtained
in good yields together with small amounts of homoallyl-
ated by-products 4. It was reported that similar by-products
were obtained in the reaction of homoallylsilanes.5a In these

M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
4685
calculations of the model compounds. It is worth noting
that in the optimized structure of g-stannyl carboation (A),
the cyclopropane ring is almost formed, indicating a strong
percaudal interaction between the empty p orbital of the
carbocation and the C±Sn s orbital. The calculations
indicated that the b-stannyl carbocation B (Fig. 1) is
15 kcal/mol more stable than the g-stannyl carbocation A.
This result is consistent with the general tendency that the
b-effect is stronger than the g-effect.11 Therefore, the
isomerization of the g-stannyl carbocation to the b-stannyl
carbocation is exothermic, although the activation energy
for this isomerization is not clear at present.
Scheme 3.
The reaction of substituted homoallylstannanes such as 2b
and 2c with aldehydes in the presence of TiCl4 also
proceeded smoothly to give the corresponding cyclopropyl-
methylated products in good yields. Especially, diastereo-
selectivity of the present reaction using homoallylstannane
having an internal double bond was remarkable. For
example, the erythro product was obtained selectively
(97/3) starting from 1c and E-3-pentenyltributylstannane
(2c: E/Zˆ88/12) (entry 5).12 The reaction of 2c with other
aldehydes such as 1d and 1e also took place stereo-
selectively to give the corresponding erythro products
(entries 6 and 7).
Scheme 4.
Highly erythro-selective addition of crotyltrialkyltins to
aldehydes has been reported by Y. Yamamoto and a
mechanism involving an acyclic transition state is
proposed.13 The stereoselectivity of the present reaction
can also be explained by an acyclic transition state model.
The addition of E homoallylstannane to the carbonyl group
seems to take place in antiperiplanar fashion to give the
erythro product selectively (Fig. 2).
cases, TiCl4 was found to be more effective than TMSOTf.
Presumably TMSOTf is not strong enough to generate
cationic species from acyl halides and aldehydes.
These reactions seem to proceed by the initial electrophilic
attack of a carbocation (E1) generated from acetals, acyl
halides, or aldehydes to the carbon±carbon double bond
of the homoallylstannane to give the carbocation g to the
tin atom, which undergoes g-elimination of the formal
stannyl cation to form a cyclopropane ring (Scheme 4).
The homoallylated product 4 seems to be produced by the
isomerization of the carbocation via hydride shift to form
b-stannyl carbocation followed by b-elimination of tin.
The reaction of 1e and (Z)-3-pentenyltributylstannane
(E/Zˆ1/.99), however, resulted in the decrease of the
selectivity (68/32) (entry 8). This result sharply contrasts
to high erythro selectivity regardless of the geometry of
the crotyl unit reported for crotylstannane reported by
Yamamoto,13 although Keck reported the lower selectivity
for the Z-crotylstannane than the E isomer.14,15 Low
selectivity of the Z isomer in the present case might be
explained in terms of the competition between the anti-
periplanar transition state and the synclinal transition
In order to get an insight into the isomerization of the
g-stannyl carbocation to the b-stannyl carbocation, their
relative stabilities were determined by molecular orbital
Figure 1. The optimized structures of: (A) CH3CHCH2CH2SnH3 cation; and (B) CH3CH2CHCH2SnH3 cation obtained by molecular orbital calculations (MP2/
LANL2DZ).

4686
M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
Figure 2. Proposed transition state of cyclopropylmethylation by the E-homoallylstannane.
Figure 3. Proposed transition state of cyclopropylmethylation by the Z-homoallylstannane.
state, although the detailed mechanism is not clear at present
(Fig. 3).
stereoselective giving the erythro products predominantly.
These reactions serve as a convenient method for the
cyclopropylmethylation of carbonyl compounds.
Conclusion
Experimental
The reactions of homoallylstannanes with carbon electro-
philes such as acetals, aldehydes, and acid halides have
been achieved in the presence of a suitable Lewis acid,
such as TMSOTf and TiCl4. Especially, the reaction
with E-3-pentenylstannane has been found to be highly
General remarks
Glass-support pre-coated (Merk silica gel 60 F254,
0.25 mm) plates were employed for analytical TLC. Flash

M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
4687
chromatography was carried out using Wako-Gel C-300.
Proton (300 MHz) and carbon (75 MHz) NMR spectra
were determined on a Varian Gemini 2000 spectrometer.
Mass spectra were obtained on a JEOL JMS SX-102A
mass spectrometer (EI, 70 eV). Isomer and diastereomer
ratios were determined by capillary GLC analyses (Simadzu
GC-14A, equipped with an OV-1 column, 0.25 mm£25 m)
and proton NMR analyses. Preparative gel permeation chro-
matography (GPC) was carried out with a Japan Analytical
Industry LC908 with GPC columns (JAIGEL 1H and 2H)
using CHCl3 as eluent. Thin-layer chromatography (TLC)
was carried out by using Merck precoated silica gel 60 F254
plates (thickness 0.25 mm).
(Z)-3-Pentenyltributylstannane (2d). To an LDA solution
(1.1 mmol) in THF (2.0 mL) was added tributhyltin hydride
(0.30 mL, 1.1 mmol) over 5 min at 2788C. After being stir-
red for 30 min at 08C, the resulting tributylstannyllithium
solution was cooled to 2788C. (Z)-3-Pentenyl tosylate
(234.2 mg, 0.98 mmol) was added to the reaction mixture
at 2788C and the solution was stirred overnight at room
temperature. Water was added and the organic materials
were extracted with ether. The organic phase was washed
with brine, and dried over MgSO4. After removal of the
solvent, the residue was puri®ed by ¯ash chromatography
to obtain the title compound (394 mg, 99%). The E/Z ratio
(1/.99) was determined by 1H NMR. TLC Rf 0.85 (hexane/
1
EtOAcˆ10/1); H NMR (CDCl3) d 0.70±1.0 (m, 17H),
3-Methyl-3-butenyltributylstannane (2b). To a lithium
diisopropylamide (LDA) solution (2.2 mmol) in THF
(5.0 mL) was added tributhyltin hydride (568 mg,
1.95 mmol) over 5 min at 2788C. After being stirred for
30 min at 08C, the resulting tributylstannyl lithium solution
was cooled to 2788C. 3-Methyl-3-butenyl tosylate (556 mg,
2.3 mmol) was added to the reaction mixture at 2788C and
the solution was stirred for 7 h at 258C. Water was added,
and the organic materials were extracted with ether. The
organic phase was washed with brine, and dried over
MgSO4. After removal of the solvent, the residue was
puri®ed by ¯ash chromatography to obtain the title
compound (660 mg, 94%, 83% purity by GC), which was
further puri®ed with GPC. TLC Rf 0.85 (hexane/
1.20±1.40 (m, 6H), 1.42±1.52 (m, 6H), 1.60 (d,
Jˆ4.5 Hz, 3H), 2.10±2.35 (m, 2H), 5.30±5.45 (m, 2H);
13C NMR (CDCl3) d 8.73, 12.57, 13.60, 23.83, 27.31,
29.16, 29.30, 122.35, 134.25; IR (neat) 2924, 1464,
1071 cm21; MS (EI) m/e (%) 303 (M1-Bu, 100), 235 (30),
177 (51); HRMS (EI) calcd for C17H36Sn±C4H9 303.1135,
found 303.1148.
2-Cyclopropyl-1-phenyl-1-methoxyethane (3a). To
a
solution of benzaldehyde dimethyl acetal (75 mL,
0.50 mmol) and 3-butenyltributylstannane (219.5 mg,
0.64 mmol) in CH2Cl2 (1.8 mL) was added TMSOTf
(100 mL, 0.55 mmol) at 2408C. The reaction mixture was
stirred at the same temperature for 3 h. The reaction was
quenched by the addition of sat. aq. NaHCO3. The mixture
was warmed to room temperature. The organic materials
were extracted with ether, and the organic phase was
washed with brine, and dried over MgSO4. After removal
of the solvent, the residue was puri®ed by ¯ash chromato-
graphy to obtain the title compound (73.1 mg, 83%). TLC Rf
1
EtOAcˆ10/1); H NMR (CDCl3) d 0.70±1.0 (m, 17H),
1.20±1.40 (m, 6H), 1.42±1.52 (m, 6H), 1.75 (s, 3H), 2.75
(t, Jˆ8.1 Hz, 2H), 4.67 (s, 1H), 4.70 (t, Jˆ1.2 Hz, 1H); 13C
NMR (CDCl3) d 6.85, 8.64, 13.60, 21.98, 27.31, 29.15,
34.75, 108.40, 149.51; IR (neat) 2920, 1649, 882 cm21
;
Anal. Calcd for C17H36Sn: C, 56.85; H, 10.10. Found: C,
56.72; H, 9.87.
1
0.27 (hexane/EtOAcˆ20/1); H NMR (CDCl3) d 20.02
(ddd, Jˆ14.4, 9.0, 5.1 Hz, 1H), 0.06 (ddd, Jˆ14.4, 9.6,
5.4 Hz, 1H), 0.30±0.50 (m, 2H), 0.60±0.70 (m, 1H), 1.47
(ddd, Jˆ13.8, 6.9, 6.9 Hz, 1H), 1.77 (ddd, Jˆ13.8, 6.9,
6.9 Hz, 1H), 3.23 (s, 3H), 4.18 (t, Jˆ6.9 Hz, 1H), 7.20±
7.40 (m, 5H); 13C NMR (CDCl3) d 4.26, 7.56, 43.10,
56.53, 84.44, 126.89, 127.51, 128.35, 142.47; IR (neat)
(E)-3-Pentenyltributylstannane (2c). To a mixture of Mg
(436 mg, 17.9 mmol) and THF (2.0 mL) was added a small
piece of iodine at room temperature, and the mixture was
stirred until a brown color disappeared. Two drops of the
solution of 1-bromo-3-pentene (E/Zˆ88/12) (2.21 g,
14.8 mmol) in THF (2.0 mL) was added to the mixture.
After the reaction was initiated, THF (20 mL) was added
to the reaction mixture. Then the remained solution of
1-bromo-3-pentene was added dropwise to the reaction
mixture at room temperature over 15 min. After being
re¯uxed for 1 h, the reaction mixture was cooled to 08C.
Tributyltin chloride (2.9 mL, 10.7 mmol) was added slowly
to the Grignard solution and the reaction mixture was stirred
for 2 h at room temperature. Saturated aq NH4Cl (1.5 mL)
was added and solid materials were removed by ®ltration.
The solvent was evaporated and the residue was puri®ed by
distillation (1358C, 1.0 mmHg) to obtain the title compound
(3.92 g, quantitative). The E/Z ratio (88/12) was determined
3090 (cyclopropane C±H) cm21
C12H16O: C, 81.77; H, 9.15. Found: C, 81.33; H, 9.10.
; Anal. Calcd for
1-Cyclopropyl-4-phenylbutan-2-one (3b).
A
typical
procedure for TiCl4 promoted cyclopropylmethylation with
homoallylstannane (2). To a solution of 3-phenylpropionyl
chloride (35.0 mg, 0.21 mmol) and 3-butenyltributylstan-
nane (70.0 mg, 0.20 mmol) in CH2Cl2 (0.60 mL) was
added slowly a solution of TiCl4 in CH2Cl2 (1.0 M,
0.22 mL, 0.22 mmol) at 2788C. The reaction mixture was
stirred at the same temperature for 3 h. After most of the
acid chloride was consumed, the reaction was quenched by
the addition of sat. aq. NaHCO3 (ca. 5 mL) at the same
temperature. The mixture was warmed to room temperature.
The organic materials were extracted with ether, and the
organic phase was washed with brine. After removal of
the solvent, the residue was treated with sat. KF/MeOH
solution (ca. 0.5 mL) for 1.5 h at room temperature. The
resulted suspension was diluted with ether and water. The
organic phase was separated and dried over MgSO4. After
the solvent was removed, the residue was puri®ed by ¯ash
chromatography to obtain the title compound (32.7 mg,
1
by GLC analysis. TLC Rf 0.85 (hexane/EtOAcˆ10/1); H
NMR (CDCl3) d 0.70±1.0 (m, 17H), 1.20±1.40 (m, 6H),
1.42±1.52 (m, 6H), 1.64 (d, Jˆ4.8 Hz, 3H), 2.10±2.35 (m,
2H), 5.30±5.50 (m, 2H); 13C NMR(CDCl3) d 8.77, 13.60,
17.76, 27.33, 29.03, 29.16, 29.66, 123.41, 134.92; IR (neat)
2921, 1464, 962 cm21; Anal. Calcd for C17H36Sn: C, 56.85;
H, 10.10. Found: C, 56.57; H, 9.80. The E stereochemistry is
consistent with the strong IR absorption at 963 cm21 which
is absent in 2d.

4688
M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
87%). TLC Rf 0.31 (hexane/EtOAcˆ10/1); 1H NMR
(CDCl3) d 0.09 (dd, Jˆ10.2, 4.5 Hz, 2H), 0.54 (ddd,
Jˆ10.5, 5.7, 4.5 Hz, 2H), 0.90±1.00 (m, 1H), 2.27 (d,
Jˆ7.2 Hz, 2H), 2.70±2.84 (m, 2H), 2.85±2.95 (m, 2H),
7.10±7.40 (m, 5H); 13C NMR (CDCl3) d 4.33, 6.15,
29.57, 43.78, 48.20, 126.11, 128.39, 128.53, 141.28,
210.28; IR (neat) 3090 (cyclopropane C±H), 1716 (CvH)
cm21; MS (EI) m/e (%) 188 (M1, 60), 159 (30), 133 (85);
HRMS (EI) calcd for C13H16O 188.1201, found 188.1204;
Anal. Calcd for C13H16O: C, 82.94; H, 8.57. Found: C,
82.74; H, 8.53.
erythro-2-Cyclopropyl-1-cyclohexylpropan-1-ol (erythro-
3g). TLC Rf 0.25 (hexane/EtOAcˆ10/1); 1H NMR
(CDCl3) d 0.06±0.12 (m, 2H), 0.40±0.52 (m, 2H), 0.68±
0.77 (m, 1H), 0.81±0.91 (m, 1H), 0.94 (d, Jˆ6.3 Hz, 3H),
0.95±1.05 (m, 2H), 1.10±1.35 (m, 3H), 1.40±1.58 (m, 3H),
1.60±1.80 (m, 3H), 1.98 (d, Jˆ12.6 Hz, 1H), 3.30 (dd,
Jˆ7.8, 3.6 Hz, 1H); 13C NMR (CDCl3) d 3.76, 3.87,
12.74, 15.42, 25.88, 26.14, 26.40, 29.00, 29.41, 40.19,
40.29, 79.92; IR (neat) 3360 (br, OH), 3075 (cyclopropane
C±H) cm21; MS (EI) m/e (%) 153 (M12C2H5, 2), 135 (10),
113 (42); HRMS (EI) calcd for C12H22O±C2H5 153.1279,
found 153.1277; Anal. Calcd for C12H22O: C, 79.06; H,
12.16. Found: C, 79.23; H, 11.91.
1-Cyclopropyl-4-phenylbutan-2-ol (3c). TLC Rf 0.11
1
(hexane/EtOAcˆ10/1), H NMR (CDCl3) d 0.00±0.20 (m,
2H), 0.40±0.60 (m, 2H), 0.68±0.81 (m, 1H), 1.35±1.45 (m,
2H), 1.71±1.85 (m, 2H), 2.68 (ddd, Jˆ13.8, 9.9, 6.9 Hz,
1H), 2.80 (ddd, Jˆ13.8, 9.6, 6.9 Hz, 1H), 3.70±3.80 (m,
1H), 7.15±7.40 (m, 5H); 13C NMR (CDCl3) d 3.54, 4.36,
7.21, 31.97, 38.68, 42.23, 71.85, 125.82, 128.44, 128.50,
142.34; IR (neat) 3350 (br, OH), 3090 (cyclopropane
C±H) cm21; MS (EI) m/e (%) 190 (M1, 12), 172 (65),
143 (30); HRMS (EI) calcd for C13H18O±H2O 172.1252,
found 172.1243.; Anal. Calcd for C13H18O: C, 82.06; H,
9.53. Found: C, 81.82; H, 9.66.
threo-2-Cyclopropyl-1-cyclohexylpropan-1-ol (threo-3g).
1
TLC Rf 0.27 (hexane/EtOAcˆ10/1); H NMR (CDCl3) d
0.04 (dt, Jˆ9.3, 5.4 Hz, 1H), 0.29 (dt, Jˆ5.4, 3.6 Hz, 1H),
0.38±0.50 (m, 1H), 0.50±0.65 (m, 2H), 0.82±0.95 (m, 1H),
0.96 (d, Jˆ0.9 Hz, 3H), 1.00±1.40 (m, 6H), 1.45±1.80
(m, 6H), 3.20±3.30 (m, 1H); 13C NMR (CDCl3) d 1.29,
4.96, 13.97, 16.93, 26.11, 26.20, 26.52 (probably a
signal of another carbon is buried), 30.50, 40.06, 40.26,
81.36; MS (EI) m/e (%) 182 (M1, 1), 164 (3), 153 (10);
HRMS (EI) calcd for C12H22O±C2H5 153.1279, found
153.1284.
1-(1-Methylcyclopropyl)-4-phenylbutan-2-ol (3d). TLC
1
Rf 0.17 (hexane/EtOAcˆ10/1), H NMR (CDCl3) d 0.20±
1-Phenylhept-6-en-3-one (4b). TLC Rf 0.33 (hexane/
1
0.38 (m, 3H), 0.39±0.45 (m, 1H), 1.06 (s, 3H), 1.22 (dd,
Jˆ13.8, 9.0 Hz, 1H), 1.63 (ddd, Jˆ14.1, 3.9, 1.2 Hz, 1H),
1.70±1.90 (m, 2H), 2.69 (ddd, Jˆ13.8, 9.6, 6.6 Hz, 1H),
2.81 (ddd, Jˆ13.8, 9.6, 6.6 Hz, 1H), 3.85±3.93 (m, 1H),
7.20±7.35 (m, 5H); 13C NMR (CDCl3) d 11.93, 12.62,
12.84, 22.65, 31.96, 39.17, 46.53, 69.80, 125.81, 128.44,
128.50, 142.39; IR (neat) 3370 (br, OH), 3067 (cyclo-
propane C±H) cm21; MS (EI) m/e (%) 204 (M1, 2), 186
(38), 157 (25); HRMS (EI) calcd for C14H20O±H2O
186.1408, found 186.1404.
EtOAcˆ10/1); H NMR (CDCl3) d 2.31 (dt, Jˆ6.6 and
6.9 Hz, 2H), 2.49 (t, Jˆ6.9 Hz, 2H), 2.74 (t, Jˆ7.2 Hz,
2H), 2.91 (t, Jˆ7.2 Hz, 2H), 4.98 (dt, Jˆ10.2, 1.8 Hz,
1H), 5.01 (dq, Jˆ16.8, 1.8 Hz, 1H), 5.84 (ddd, Jˆ16.8,
10.2, 6.6 Hz, 1H), 7.15±7.40 (m, 5H); 13C NMR (CDCl3)
d 27.61, 29.62, 41.95, 44.30, 115.32, 126.17, 128.39,
128.57, 137.13, 141.17, 209.47; IR (neat) 2926, 1717
(CvH), 1455 cm21; MS (EI) m/e (%) 188 (M1, 30), 133
(65), 105 (100); HRMS (EI) calcd for C13H16O 188.1201,
found 188.1205. Anal. Calcd for C13H16O: C, 82.94; H,
8.57. Found: C, 82.74; H, 8.53.
erythro-4-Cyclopropyl-1-phenylpentan-3-ol (3e). TLC Rf
0.17 (hexane/EtOAcˆ10/1), 1H NMR (CDCl3) d 0.02±0.10
(m, 1H), 0.12±0.22 (m, 1H), 0.45 (dd, Jˆ8.7, 2.1 Hz, 2H),
0.58±0.70 (m, 1H), 0.72±0.84 (m, 1H), 0.97 (d, Jˆ6.6 Hz,
3H), 1.70±1.95 (m, 2H), 2.65 (ddd, Jˆ13.8, 9.9, 6.6 Hz,
1H), 2.86 (ddd, Jˆ13.8, 9.9, 6.6 Hz, 1H), 3.62 (dt, Jˆ9.0,
3.9 Hz, 1H), 7.15±7.30 (m, 5H); 13C NMR (CDCl3) d 3.01,
4.31, 14.04, 14.47, 32.58, 36.33, 44.03, 75.48, 125.82,
128.44, 128.50, 142.45; IR (neat) 3370 (br, OH), 3085
(cyclopropane C±H) cm21; Anal. Calcd for C14H20O: C,
82.30; H, 9.87. Found: C, 82.16; H, 9.75.
1-Phenylhept-6-en-3-ol (4c). TLC Rf 0.11 (hexane/
EtOAcˆ10/1), 1H NMR (CDCl3) d 1.42 (d, Jˆ5.1 Hz,
1H), 1.54±1.64 (m, 2H), 1.70±1.82 (m, 2H), 2.05±2.24
(m, 2H), 2.68 (ddd, Jˆ13.8, 9.3, 6.9 Hz, 1H), 2.81 (ddd,
Jˆ13.8, 9.3, 6.9 Hz, 1H), 3.62±3.72 (m, 1H), 4.96 (dt,
Jˆ10.2, 1.8 Hz, 1H), 5.04 (dq, Jˆ17.7, 1.8 Hz, 1H), 5.84
(ddd, Jˆ17.7, 10.2, 6.9 Hz, 1H), 7.15±7.40 (m, 5H); 13C
NMR (CDCl3) d 29.97, 31.96, 36.51, 39.12, 70.94,
114.92, 125.90, 128.50 (2 carbons), 138.59, 142.21; IR
(neat) 3400 (OH), 1641, 1454 cm21; MS (EI) m/e (%) 190
(M1, 3), 172 (40), 130 (65); HRMS (EI) calcd for C13H18O±
H2O 172.1252, found 172.1251.
erythro-2-Cyclopropyldecan-3-ol (3f). TLC Rf 0.25
(hexane/EtOAcˆ10/1); 1H NMR (CDCl3) d 0.02±0.10
(m, 1H), 0.14±0.20 (m, 1H), 0.47 (dd, Jˆ8.4, 2.1 Hz, 2H),
0.60±0.80 (m, 2H), 0.87 (t, Jˆ8.4 Hz, 3H), 0.97 (d,
Jˆ6.6 Hz, 3H), 1.20±1.60 (m, 12H), 3.55±3.65 (m, 1H);
13C NMR (CDCl3) d 3.10, 4.21, 13.77, 13.97, 14.63,
22.54, 26.17, 29.22, 29.60, 31.76, 34.60, 43.84, 75.97; IR
(neat) 3360 (br, OH), 3075 (cyclopropane C±H) cm21; MS
(EI) m/e (%) 180 (M12H2O, 2), 169 (10), 151 (2); HRMS
(EI) calcd for C13H26O±C2H5 169.1592, found 169.1591;
Anal. Calcd for C13H26O: C, 78.72; H, 13.21. Found: C,
78.51; H, 12.95.
Molecular orbital calculations
The ab initio calculations were carried out using the
gaussian 98 program16 at the MP2/LANL2DZ level.
All geometries were fully optimized and all the
optimized structures were local minima according to the
vibration frequency analyses. Relative energies were
corrected for ZPE (zero point energy) calculated at MP2/
LANL2DZ.

M. Sugawara, J. Yoshida / Tetrahedron 56 (2000) 4683±4689
4689
9. Seyferth, D.; Weiner, M. A. J. Am. Chem. Soc. 1962, 84, 361.
10. Tsunoda, T.; Suzuki, M.; Noyori, R. Tetrahedron Lett. 1980,
21, 71.
Acknowledgements
This work was supported by a Grant-in-Aid for Scienti®c
Research from the Ministry of Education, Science, Sports
and Culture, Japan.
11. Lambert, J.B.; Zhao, Y.; Emblide, R.W.; Salvador, L.A.; Liu,
X.; So, J.-H.; Chelius, E.C. Acc. Chem. Res. 1999, 32, 183 and
references cited therein. See also Ref. 4a.
12. The erythro stereochemistry was determined by comparison
with an authentic sample, which was prepared by the cyclo-
propanation by a zinc carbenoid of the corresponding erythro
homoallylalcohol. cf. Yamamoto, Y.; Yatagai, H.; Naruta, Y.;
Maruyama, K. J. Am. Chem. Soc. 1980, 102, 7107.
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