Beyond the corey reaction II: Dimethylenation of sterically congested ketones

Article abstract of DOI:10.1021/jo502021x

Bulky methyl ketones show significantly decreased reactivities toward the Corey-Chaykovsky methylenation reagent dimethylsulfoxonium methylide (DMSM). The excess of base and temperature increase opens an alternative reaction channel that instead leads to

Full text of DOI:10.1021/jo502021x

Note
pubs.acs.org/joc
Terms of Use
Beyond the Corey Reaction II: Dimethylenation of Sterically
Congested Ketones§
Anastasiya V. Barabash,#,‡ Ekaterina D. Butova,# Igor M. Kanyuk,# Peter R. Schreiner,*,‡
and Andrey A. Fokin*,#,‡
#Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev, Ukraine
‡Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
S
* Supporting Information
ABSTRACT: Bulky methyl ketones show significantly decreased
reactivities toward the Corey-Chaykovsky methylenation reagent
dimethylsulfoxonium methylide (DMSM). The excess of base and
temperature increase opens an alternative reaction channel that instead
leads to the corresponding cyclopropyl ketones. Computations suggest
that the initial reaction step involves the methylene group transfer from
DMSM on the ketone enolate followed by the intramolecular cyclization.
The key step is associated with a barrier of 22 3 kcal mol−1 and is driven
by exothermic elimination of DMSO.
The Corey-Chaykovsky reaction utilizes dimethylsulfoxonium
methylide (DMSM) for the preparation of oxiranes from
carbonyl compounds in DMSO (a, Scheme 1).1 At elevated
the same time the classic Corey-Chaykovsky methylenation of
1 with DMSM, which is known to proceed through the same
betaine intermediate,3,8 still occurs through path a readily at
room temperature to give the corresponding oxirane in up to
88% yield.9
Hence, the experiments suggest that base excess and high
temperatures may decrease the yield of the reaction of bulky
ketones with sulfur ylides and may be associated with the
competitive yet unknown reactions. These are the focus of the
present work, where we first carefully analyzed the reaction of
bulky 1 at 130 °C with DMSM in DMSO with an excess of
base (Scheme 2). As expected,4−6,10 2-(1-adamantyl)butadiene-
1,3 (2) forms in a 17% yield as the main product together with
a mixture of sulfur-containing compounds (3) similar to those
described earlier for cyclic ketones.10
Scheme 1. Reaction of Ketones (1) with
Dimethylsulfoxonium Methylide (DMSM)
Unexpectedly, 1-adamantyl cyclopropyl ketone (4) was also
isolated in 13% yield. Such formal α-dimethylenation of the
methyl group of 1 has, to the best of our knowledge, not been
observed before in the reactions of methylketones with ylides.
Evidently, the adamantyl group hinders the attack of the
reagent on the carbonyl group as this group remains unchanged
in the reaction of 1 to 4. We next studied the reactivity of
sterically congested diamantyl ketones 5 and 6 that are
structurally closely related to 1 (Scheme 3). While the steric
demand of the cage moiety in 5 is similar to that in 1, medial
ketone 6 is even more hindered due to the presence of
hydrogens in the positions C13 and C3. Unsurprisingly, 4-
diamantyl methyl ketone (5) with DMSM gives the same
product distribution as 1 under the same reaction conditions. In
contrast, 1-diamantyl methyl ketone (6) gives 1-diamantyl
temperatures and with excess ylide further ring expansion to
oxetanes2 (b) and even to oxolanes (c) takes place.3 At higher
temperatures and with excess of base ketones can be
transformed directly to 1,3-dienes (diolefination, d)4−6 as well
as to unsaturated sulfoxides (f) and sulfides (e), whose ratios
depend on the amounts of DMSO employed. Steric factors
influence the high-temperature reactions (paths d and e)
substantially. For example, the yields of the diolefination (path
d) drop considerably for bulky ketones (to ca. 20% for 1-
adamantyl methyl ketone (1, R1 = H; R2 = adamantyl).6,7 At
Received: September 2, 2014
© XXXX American Chemical Society
A
dx.doi.org/10.1021/jo502021x | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
Scheme 2. Reaction of 1-Adamantyl Methyl Ketone (1) with Dimethylsulfoxonium Methylide in the Presence of Base Excess in
DMSO (SCG = Sulfur Containing Group)
Scheme 3. Direct α-Dimethylenation of Sterically Congested
Ketones (Yields Are Preparative)
Scheme 4. Preparation and Transformations of Intermediate
15 under the α-Dimethylenation Conditions (Yields Are
Preparative)
ketones with DMSM in DMSO,13,14 giving 10 in high yield
(modeling the final step F → G in Scheme 3).
Obviously, the bottleneck step B → D (Scheme 3) requires
careful scrutiny, as it involves interaction of two electron-rich
species. To probe this hypothesis, we modeled the acetone
enolate anion (B, R = CH3) reaction with DMSM computa-
tionally (Figure 1). In order to account for dispersion
interactions in the common B3LYP functional, which does
not fully include noncovalent interactions,15−17 we utilized the
functionals B3PW91,18 B3LYP-D3,19 as well as the B3LYP-
cyclopropyl ketone (10) exclusively. In addition, we found that
a number of other sterically congested ketones, namely
2′,3′,4′,5′,6′-pentamethyl acetophenone (7) and 1-(1-
methylcyclohexyl)ethanone (8), undergo formal α-dimethyle-
nation to give the corresponding cyclopropyl ketones (11 and
12, see Experimental Section for details). Apparently, the attack
of DMSM on the carbonyl group and subsequent formation of
the tetrahedral intermediate is hampered for such bulky
ketones. Indeed, for highly sterically congested ketones such
as 6 and 7, only the methyl group of the acetyl function is
involved in the transformations with DMSM. These ketones are
completely inert under Corey-Chaykovsky conditions without
base excess: only the starting material was isolated
quantitatively from the reaction mixtures even under prolonged
heating.
A rational explanation of these experimental facts begins with
simple base-catalyzed enolization of ketone A to B that opens
an alternative reaction channel. The formal attack of DMSM
onto the enolate anion B through transition structure C results
in the formation of cyclopropane alcoholate anion D that gives
alcohol E in DMSO (Scheme 3).
Further oxidative fragmentation of E to F is well-established
in the literature for various cyclopropanols11 and also was
shown for the transformation of independently prepared
intermediate E (R = 1-diamantyl, 15), under the same reaction
conditions (Scheme 4). Alcohol 15 was prepared from 6
through TMS-derivative 13, its cyclopropanation via a modified
Simmons-Smith procedure12 (see Experimental Section for
details) followed by hydrolysis of thus formed 14 with
tetrabutyl ammonium fluoride hydrate. We have found that at
elevated temperatures, 15 forms 1-diamantyl vinyl ketone (16),
confirming the possibility of the oxidative fragmentation of
hydroxyl cyclopropanes in the DMSO/DMSM system.
Subsequent cyclopropanation of 16 with DMSM involves the
well-known methylenation of vinyl ketones to cyclopropyl
Figure 1. Relative enthalpy for the reaction of acetone enolate anion
(B, R = CH3) with dimethylsulfoxonium methylide (DMSM)
computed at different levels of theory [PCM (DMSO), relative
ΔH298 in kcal mol−1, critical interatomic distances in angstroms,
B3PW91/6-31+G(d,p)].
B
dx.doi.org/10.1021/jo502021x | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
D3(BJ) with Becke-Johnson damping,20 which partially
addresses such effects, and the highly parametrized M06-2X
functional,21 which accounts for medium-range correlation. For
comparison, the MP2 as well as spin-component-scaled MP2
(SCS-MP2)22,23 ab initio methods were employed. Since
conventional gas-phase computations overestimate the energies
of highly polarized structures, we employed a polarizable
continuum model (PCM) to account for solvent effects.24 This
solvation model was previously successfully used to model
reaction of sulfur ylides with ketones.2,10 The direct attack of
DMSM on the acetone enolate anion (B) computed at different
Figure 2) were engaged for comparative analysis. Due to the
σ−π attractions between the methyl groups of DMSM and the
aromatic rings, the barriers for the methylenation strongly
depend on computational method (Figure 2). Unsurprisingly,
the barrier of 10.6 kcal mol−1 for the methylenation of
nitrobenzene through TS M at M06-2X, which is typically
successful in describing the σ−π interactions, is very close to
the a priori dispersion-sensitive MP2 value (12.0 kcal mol−1)
and is consistent with the experimental data that this reaction
proceeds smoothly already at room temperature.27 While the
B3LYP-D3 and B3LYP-D3(BJ) barriers are close to the above
values, the barriers computed with the B3LYP and B3PW91
functionals are substantially higher (15−17 kcal mol−1). The
dispersion interactions stabilize the TS N for the methylenation
of anthracene even more (by ca. 10 kcal mol−1). However, the
absolute barriers computed for this reaction generally are 5−7
kcal mol−1 higher than that for the methylenation of
nitrobenzene. This agrees nicely with the experiment where
the methylenation of anthracene with DMSM proceeds at
100 °C.26
levels of theory requires 22
3 kcal mol−1 through the
transition structure (TS) C that is best viewed as the
nucleophilic substitution at the CH2 group of the ylide with
DMSO as the leaving group (Figure 1).
The DFT and ab initio barriers heights are consistent with
the experimental result that the reaction requires heating. The
relatively high thermodynamic stability of the leaving group
(DMSO) leads to an exothermic first step (−15
3 kcal
mol−1) to give minimum H. Further transformation of the
anionic part of H through TS K is virtually barrierless and
exothermically yields the cyclopropanol anion (D) that
additionally releases 13 2 kcal mol−1. Note the reaction is
only slightly sensitive to steric hindrance as the transition
structure L (Figure 2) for the attack of DMSM on the sterically
Our computations show that the C-methylenations of
enolate anions and aromatic substrates are related mechanis-
tically and best viewed as the SN2 substitution at the methylene
group of DMSM. Remarkably, the barriers for methylene
transfer from DMSM to negatively charged enolate anions (TS
L) and uncharged anthracene (TS N) are comparable. The key
geometrical parameters differ only slightly (TS L is slightly less
tightly bound, Figure 2).
We conclude that high temperature and excess of base are
two key factors that can drastically alter the course of the classic
Corey-Chaykovsky reaction, resulting in the methylenation of
enolate anions with DMSM. The driving force of the reaction
between these two electron-rich species is provided by the high
exothermicity of the elimination of DMSO that serves as a good
leaving group in the SN2-type reaction. This reaction parallels
the well-established electrophilic methylenation of aromatic
compounds with sulfur ylides but has never been observed
before for carbonyl compounds. In the presence of base excess,
bulky methyl ketones may follow either diolefination or
dimethylenation paths, while the Corey-Chaykovsky reaction
is completely suppressed under these conditions.
Figure 2. Transition structures for the attack of DMSM on 1-
diamantyl methyl enolate (L), nitrobenzene (M), and anthracene (N)
computed at different levels of theory [PCM (DMSO), relative ΔH0‡
in kcal mol−1 and critical interatomic distances in angstroms].
EXPERIMENTAL SECTION
■
General Information. NMR spectra were recorded at 400 MHz
(1H) spectrometer with TMS as the internal standard. High-resolution
mass spectra (HRMS) were recorded using electron impact ionization
on a double-focusing sector-field mass spectrometer. Products were
purified by chromatography on 100−160 mesh silica gel. Commer-
cially available reagents and solvents were used without further
purification.
congested ketone 6 enolate anion is close structurally and
energetically to C (Figures 1 and 2).25 However, as diamantyl
ketone 6 is more polarizable (owing to its size), it is more
sensitive to the method employed; while the B3PW91, M06-2X
and B3LYP computations give barriers within the 23−25 kcal
mol−1, the B3LYP-D3 and B3LYP-D3(BJ) methods lower the
barrier by ca. 5 kcal mol−1, reflecting the growing contributions
from stabilizing dispersion interactions. We thus compared this
reaction with other known examples of direct attacks of DMSM
onto the electron-rich species such as aromatic compounds26,27
(vicarious nucleophilic substitution28), where the contributions
from the noncovalent interactions are expected to be
substantial due to the presence of effective dispersion energy
π-donors.29
General Procedure for α-Dimethylenation of Sterically
Congested Methyl Ketones. To dry NaOH (0.384 g, 9.6 mmol),
dry DMSO (4 mL) was added, stirred for 15 min and then
trimethylsulfoxonium iodide (0.694 g, 3.2 mmol) was added. The
mixture was heated to 90−130 °C, and a solution of ketone (1.6
mmol) in DMSO (2 mL) was added. The mixture was stirred under
argon atmosphere for 1−24 h, diluted with water, and extracted with
hexane (3 × 15 mL). The combined organic layers were washed with
water and brine and were concentrated under reduced pressure to give
the crude product. Purification with column chromatography (SiO2,
hexane-ether, 95:5) gave the starting ketone together with the pure
cyclopropyl ketones 4 and 9−12 in 11−40% preparative yields.
1-Adamantyl Cyclopropyl Ketone (4) was synthesized at 130 °C, during
23 h and isolated in 13% (0.035 g) preparative yield as colorless solid,
The experimentally known C-methylenations of nitro-
benzene27,30 and anthracene26 with DMSM (TSs M and N,
mp 61−62 °C (hexane). H NMR (400 MHz, CDCl3): δ 0.68−0.77
1
C
dx.doi.org/10.1021/jo502021x | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
(m, 2 H), 0.83−0.89 (m, 2 H), 1.60−1.75 (m, 6 H), 1.78−1.87 (m, 6
H), 2.00 (bs, 3 H), 2.07−2.16 (m, 1 H). 13C NMR (100 MHz,
CDCl3): δ 10.6 (CH2), 15.0 (CH), 28.0 (CH), 36.7 (CH2), 38.2
(CH2), 46.4 (C), 215.2 (C). HRMS: calcd for C14H20O, 204.1514;
found, 204.1521.
NH4Cl and brine, dried over anhydrous NaSO4 and concentrated in
vacuo to give 1-(1-diamantyl)(trimethylsiloxy)cyclopropane (14)
(2.13 g). Purification by chromatography (SiO2, hexane) gave
analytically pure 1-(1-diamantyl)(trimethylsiloxy)cyclopropane (14)
(1.88 g, 90%) as a viscous oil. 1H NMR (400 MHz, CDCl3): δ 0.08 (s,
9 H), 0.68−0.72 (m, 2 H), 0.72−0.82 (m, 2 H), 1.36 (d, 2 H, J = 12.8
Hz), 1.54 (bs, 2 H), 1.58−1.71 (m, 9 H), 1.71−1.83 (m, 3 H), 1.84−
1.90 (m, 1 H), 2.20 (d, 2 H, J = 12.8 Hz). 13C NMR (100 MHz,
CDCl3): δ 1.7 (CH3), 12.8 (CH2), 25.7 (CH), 27.5 (CH), 34.3
(CH2), 37.2 (CH), 38.0 (CH), 38.0 (CH2), 39.0 (CH2), 39.3 (CH),
39.6 (C), 41.9 (CH2), 62.6 (C). HRMS: calcd for C20H32OSi,
316.2222; found, 316.2220.
1-(1-Diamantyl)cyclopropanol (15). To 1-(1-diamantyl)-
(trimethylsiloxy)cyclopropane (14) (1 g, 0.003 mol), a solution of
TBAF × 3H2O (1.196 g, 0.0037 mol) in diethyl ether (5 mL) was
added, stirred for 1 h at room temperature, and partitioned between
diethyl ether and water (1:1). The mixture was extracted three times
with diethyl ether (3 × 5 mL). The combined organic layers were
washed with a saturated solution of NH4Cl and brine, dried over
anhydrous NaSO4, and concentrated in vacuo to give 1-(1-diamantyl)-
cyclopropanol (15) (0.76 g, 99%) as white crystals, mp 105−107 °C
(hexane). 1H NMR (400 MHz, CDCl3): δ 0.68−0.75 (m, 2 H), 0.75−
0.82 (m, 2 H), 1.43 (d, 2 H, J= 12.8 Hz), 1.59 (bs, 2 H), 1.63−1.73
(m, 9 H), 1.75−1.87 (m, 4 H), 1.87−1.93 (m, 1 H), 2.15 (d, 2 H, J =
12.8 Hz). 13C NMR (100 MHz, CDCl3): δ 14.1 (CH2), 25.7 (CH),
27.3 (CH), 34.3 (CH2), 37.0 (CH), 37.1 (C), 37.8 (CH), 37.9 (CH2),
38.8 (CH2), 39.0 (CH), 41.8 (CH2), 60.6 (C). HRMS calcd for
C17H24O, 244.1827; found, 244.1834.
4-Diamantyl Cyclopropyl Ketone (9) was synthesized at 130 °C,
during 23 h and isolated in 20% (0.04 g) preparative yield as colorless
solid, mp 82−83 °C (hexane). 1H NMR (400 MHz, CDCl3): δ 0.76−
0.83 (m, 2 H), 0.91−0.96 (m, 2 H), 1.69−1.78 (m, 10 H), 1.79−1.87
(m, 7 H), 1.88−1.93 (m, 2 H), 2.15−2.23 m (1 H). 13C NMR (100
MHz, CDCl3): δ 10.6 (CH2), 15.3 (CH), 25.6 (CH), 36.7 (CH), 37.3
(CH), 37.7 (CH2), 39.1 (CH2), 44.7(C), 215.4 (C). HRMS: calcd for
C18H24O, 256.1827; found, 256.1819. MS, m/z (Irel, %): 256 (100)
[M]+, 199 (7), 187 (12), 157 (15), 131 (10), 105 (16), 91 (20).
1-Diamantyl Cyclopropyl Ketone (10) was synthesized at 130 °C,
during 21 h and isolated in 40% (0.023 g) preparative yield as colorless
solid, mp 60−61 °C (hexane). 1H NMR (400 MHz, CDCl3): δ 0.76−
0.84 (m, 2 H), 0.94−0.98 (m, 2 H), 1.52−1.58 (m, 2 H), 1.62−1.68
(m, 4 H), 1.69−1.80 (m, 8 H), 1.85−1.90 (bs, 2 H), 1.92−1.98 (m, 1
H), 2.15−2.23 (m, 1 H), 2.25−2.31 (m, 2 H). 13C NMR (100 MHz,
CDCl3): δ 10.7 (CH2), 14.7 (CH), 25.5 (CH), 26.4 (CH), 35.1
(CH2), 36.9 (CH), 37.2 (CH), 37.7 (CH2), 37.8 (CH), 38.0 (CH2),
40.8 (CH2), 52.5 (C), 215.2 (C). HRMS: calcd for C18H24O,
256.1827; found, 256.1832. Mass Spectra, m/z (Irel, %): 256 (100)
[M]+, 199 (7), 187 (12), 157 (15), 131 (10), 105 (16), 91 (20).
2′,3′,4′,5′,6′-Pentamethylphenyl Cyclopropyl Ketone (11) was synthe-
sized at 90 °C, during 21 h and isolated in 11% (0.04 g) preparative
1
yield as colorless solid, mp 68−70 °C (hexane). H NMR (400 MHz,
CDCl3): δ 1.03−1.11 (m, 2 H), 1.24−1.32 (m, 2 H), 2.15−2.25 (m, 1
H), 2.18 (s, 6 H), 2.2 (s, 6 H), 2.25 (s, 3 H). 13C NMR (100 MHz,
CDCl3): δ 12.2 (CH2), 16.0 (CH3), 16.7 (CH3), 17.5 (CH3), 23.7
(CH), 127.8 (C), 133.0 (C), 135.4 (C), 141.0 (C), 212.1 (C). HRMS:
calcd for C15H20O, 216.1514; found, 216.1511.
1-Diamantyl Vinyl Ketone (16). To NaH (0.295 g, 12.3 mmol),
DMSO (16 mL) was added and stirred at 80 °C for 15 min. Then
trimethylsulfoxonium iodide (2.705 g, 12.3 mmol) was added, heated
to 110 °C and a solution of 1-(1-diamantyl)cyclopropanol (15) (0.3 g,
1.2 mmol) in DMSO (8 mL) was added. The mixture stirred for 21 h,
diluted with water, and extracted with hexane (3 × 15 mL). The
combined organic layers were washed with water, brine, and
concentrated under reduced pressure to give crude 1-diamantyl vinyl
ketone (16) (0.29 g). After column chromatography (SiO2, hexane)
and crystallization (hexane), white crystals (0.21 g, 67%) were
obtained. 1H NMR (400 MHz, CDCl3): δ 1.48−1.60 (m, 4 H), 1.62−
1.67 (m, 2 H), 1.67−1.80 (m, 8 H), 1.87 (bs, 2 H), 1.92−1.98 (m, 1
H), 2.22 (bs, 2 H), 5.64 (dd, 1 H, J = 11 Hz, J = 2 Hz), 6.38 (dd, 1 H, J
= 17.2 Hz, J = 2 Hz), 6.86 (dd, 1 H, J = 17.2 Hz, J = 11 Hz). 13C NMR
(100 MHz, CDCl3): δ 25.4 (CH), 26.3 (CH), 34.8 (CH2), 36.7 (CH),
37.5 (CH), 37.6 (CH2), 37.8 (CH2), 40.4 (CH2), 51.1 (C), 77.24
(CH), 128.4 (CH2), 130.3 (CH), 204.3 (C). HRMS calcd for
C17H22O, 242.1671; found, 242.1669.
1-Diamantyl Cyclopropyl Ketone (10) from 1-Diamantyl Vinyl
Ketone (16). To NaOH (0.068 g, 1.24 mmol), trimethylsulfoxonium
iodide (0.09g, 0.4 mmol) and DMSO (2 mL) were added. The
mixture was heated to 110 °C, and a solution of 1-diamantyl vinyl
ketone (16) (0.05 g, 0.2 mmol) in DMSO (1 mL) was added. The
mixture was stirred for 3 h, diluted with water, and extracted with
hexane (3 × 15 mL). The combined organic layers were washed with
water and brine and were concentrated under reduced pressure to give
1-diamantyl cyclopropyl ketone (10) (0.04 g, 76%) identical to the
sample obtained earlier.
Cyclopropyl (1-Methyl)-cyclohexyl Ketone (12) was synthesized at
100 °C, during 26 h and isolated in 17% (0.113 g) preparative yield as
1
colorless oil. H NMR (400 MHz, CDCl3): δ 0.78−0.86 (m, 2 H),
0.92−1.00 (m, 2 H), 1.15 (s, 3 H), 1.23−1.60 (m, 8 H), 1.99−2.01
(m, 2 H), 2.12−2.23 m (1 H). 13C NMR (100 MHz, CDCl3): δ 10.6
(CH2), 15.7 (CH3), 23.0 (CH2), 24.9 (CH), 26.0 (CH2), 34.9 (CH2),
48.2 (C), 214.4 (C). HRMS: calcd for C11H18O, 166.1358; found,
166.1345.
1-(1-Diamantyl)-1-(trimethylsiloxy)ethene (13). To diisopropyl-
amine (3.11 mL, 0.022 mol) dry THF (54 mL) was added, cooled to
−10 °C, and n-BuLi (9.1 mL 2.5 M, 0.022 mol) was added dropwise
via a syringe. After stirring for 30 min, 1-diamantyl methyl ketone (2d)
(4 g, 0.017 mol) in dry THF (17.5 mL) was added dropwise. Reaction
mixture was stirred additionally for 1 h, and chlorotrimethylsilane
(4.08 mL, 0.032 mol) was added in one portion while stirring. The
resulting mixture was stirred at room temperature for 1 h and then
partitioned between hexane and cold aqueous NaHCO3 (1:1). The
organic layer was dried and concentrated to leave residual liquid (7.2
g) containing the crude silyl ether 7. Chromatographic purification
(neutral Al2O3, hexane-ether, 9:1) gave white crystals of silyl ether 7
(4.88 g, 93%), mp 53−54 °C (hexane). 1H NMR (400 MHz, CDCl3):
δ 0.24 (s, 9 H), 1.40 (d, 2 H, J = 12.5 Hz), 1.57−1.77 (m, 10 H),
1.80−1.90 (m, 3 H), 1.95 (bs, 2 H), 2.07 (d, 2 H, J = 12.5 Hz), 4.08 (s,
2 H). 13C NMR (100 MHz, CDCl3): δ 0.2 (CH3), 25.8 (CH), 27.3
(CH), 33.9 (CH2), 37.2 (CH), 37.3 (CH), 38.0 (CH2), 38.1 (CH),
38.5 (CH2), 43.9 (C), 44.4 (CH2), 86.9 (CH2), 164.8 (C). HRMS:
calcd for C19H30OSi, 302.2066; found, 302.2060.
ASSOCIATED CONTENT
■
S
* Supporting Information
1-(1-Diamantyl)-1-(trimethylsiloxy)cyclopropane (14). In a flame-
dried two-neck round-bottom flask, 1-(1-diamantyl)(trimethylsiloxy)-
ethene (7) (2 g, 0.0066 mol) was dissolved in hexane (12 mL), cooled
to −10 °C, and diiodomethane (21.13 g, 0.08 mol) was added. After 5
min diethylzinc solution in hexane (79.5 mL, 1 M, 0.08 mol) was
added dropwise over 1 h 20 min. The reaction mixture was allowed to
warm to room temperature and was stirred additionally for 14 h,
partitioned between diethyl ether and cold aqueous NH4Cl (1:1). The
mixture was extracted three times with diethyl ether (3 × 50 mL). The
combined organic layers were washed with a saturated solution of
Computational details, copies of NMR spectra, and xyz-
coordinates of optimized species. This material is available free
of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
■
Corresponding Authors
*E-mail: prs@uni-giessen.de. Fax: +641-99-34309.
*E-mail: aaf@xtf.kpi.ua. Fax: +38-044-2369774.
D
dx.doi.org/10.1021/jo502021x | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
(26) Metzger, H.; Konig, H.; Seelert, K. Tetrahedron Lett. 1964, 5,
867.
(27) Traynelis, V. J.; McSweeney, S. J. V. J. Org. Chem. 1966, 31, 243.
(28) Makosza, M.; Wojciechowski, K. Liebigs Ann. 1997, 1805.
(29) Grimme, S.; Huenerbein, R.; Ehrlich, S. ChemPhysChem 2011,
12, 1258.
Notes
The authors declare no competing financial interest.
§For Part 1 see ref 10.
ACKNOWLEDGMENTS
■
(30) Haiss, P.; Zeller, K.-P. Eur. J. Org. Chem. 2011, 295.
This work was supported by the Deutsche Forschungsgemein-
schaft, the Ministry of Science and Education of the Ukraine,
Ukrainian Basic Research Fund, and the Fonds der Chemischen
Industrie. A.V.B. thanks the Deutsche Akademische Austausch-
dienst (DAAD) for a fellowship and the opportunity to work in
Germany.
REFERENCES
■
(1) Corey, E. J.; Chaykovsky, M. J. Am. Chem. Soc. 1965, 87, 1353.
(2) Okuma, K.; Tanaka, Y.; Kaji, S.; Ohta, H. J. Org. Chem. 1983, 48,
5133.
(3) Butova, E. D.; Barabash, A. V.; Petrova, A. A.; Kleiner, C. M.;
Schreiner, P. R.; Fokin, A. A. J. Org. Chem. 2010, 75, 6229.
(4) Yurchenko, A. G.; Melnik, N. N.; Likhotvorik, I. R. Tetrahedron
Lett. 1989, 30, 3653.
(5) Yurchenko, A. G.; Kirii, A. V.; Mel’nik, N. N.; Likhotvorik, I. R.
Zh. Org. Khim. 1990, 26, 2230.
(6) Yurchenko, A. G.; Kyrij, A. B.; Likhotvorik, I. R.; Melnik, N. N.;
Zaharzh, P.; Bzhezovski, V. V.; Kushko, A. O. Synthesis 1991, 5, 393−
394.
(7) Fokin, A. A.; Kushko, A. O.; Kirij, A. V.; Yurchenko, A. G.;
Schleyer, P. v. R. J. Org. Chem. 2000, 65, 2984.
(8) Aggarwal, V. K.; Harvey, J. N.; Richardson, J. J. Am. Chem. Soc.
2002, 124, 5747.
(9) Shiryaev, A. K.; Moiseev, I. K. Zh. Obshch. Khim. 1988, 58, 1680.
(10) Butova, E. D.; Fokin, A. A.; Schreiner, P. R. J. Org. Chem. 2007,
72, 5689.
(11) Li, L.-Z.; Xiao, B.; Guo, Q.-X.; Xue, S. Tetrahedron 2006, 62,
7762−7771.
(12) Borcard, F.; Godinat, A.; Staedler, D.; Blanco, H. C.; Dumont,
A.-L.; Chapuis-Bernasconi, C.; Scaletta, C.; Applegate, L. A.; Juillerat,
F. K.; Gonzenbach, U. T.; Gerber-Lemaire, S.; Juillerat-Jeanneret, L.
Bioconjugate Chem. 2011, 22, 1422.
(13) Corey, E. J.; Chaykovsky, M. J. Am. Chem. Soc. 1962, 84, 3782.
(14) Paxton, R. J.; Taylor, R. J. K. Synlett 2007, 633.
(15) Check, C. E.; Gilbert, T. M. J. Org. Chem. 2005, 70, 9828.
(16) Tirado-Rives, J.; Jorgensen, W. L. J. Chem. Theory Comput. 2008,
4, 297.
(17) Wodrich, M. D.; Corminboeuf, C.; Schleyer, P. v. R. Org. Lett.
2006, 8, 3631.
(18) Perdew, J. P.; Chevary, J. A.; Vosko, S. H.; Jackson, K. A.;
Pederson, M. R.; Singh, D. J.; Fiolhais, C. Phys. Rev. B 1992, 46, 6671.
(19) Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. J. Chem. Phys.
2010, 132, 154104.
(20) Grimme, S.; Ehrlich, S.; Goerigk, L. J. Comput. Chem. 2011, 32,
1456.
(21) Truhlar, D. G.; Zhao, Y. Theor. Chem. Acc. 2008, 120, 215.
(22) Grimme, S. J. Chem. Phys. 2003, 118, 9095.
(23) Takatani, T.; Sherrill, C. D. Phys. Chem. Chem. Phys. 2007, 9,
6106.
(24) Miertus, S.; Scrocco, E.; Tomasi, J. J. Chem. Phys. 1981, 55, 117.
(25) We also computed the alternative “normal” Corey-Chaykovsky
reaction path for 6 (i.e., the attack of DMSM on the carbonyl group
with formation of the corresponding oxirane. The formation of the
tetrahedral intermediate (betaine) requires a barrier of only 8 kcal
mol−1 for 6 [M06-2X-PCM/6-31G(d,p)], in accordance with the
previously found barriers for the methylenation of sterically
unhindered ketones [ Aggarwal, V. K.; Harvey, J. N.; Richardson, J.
J. Am. Chem. Soc. 2002, 124, 5747 ] However, subsequent DMSO loss
and formation of the oxirane requires ca. 18 kcal mol−1, which is
comparable with the computed for the direct attack of DMSM on the
enolate anion of 6.
E
dx.doi.org/10.1021/jo502021x | J. Org. Chem. XXXX, XXX, XXX−XXX