One-pot, asymmetric and diastereoselective four-component synthesis of polyfunctional (Z)-alkenyl methyl sulfones with three stereogenic centers

Article abstract of DOI:10.1002/1522-2675(200206)85:6<1674::AID-HLCA1674>3.0.CO;2-2

The reaction of 1-(trimethylsilyloxy)cyclopentene (9) with (±)-1,3,5-triisopropyl-2-(1-(RS)-[[(1E)-2-methylpenta-1, 3-dienyl]oxy]ethyl)benzene ((±)-4a) in SO₂/CH₂Cl₂ containing (CF₃SO₂)₂NH, followed by treatment with Bu₄NF and MeI gave a 3.0:1 mixture of (±)-(2RS)-2{(1RS,2Z,4SR)-2-methyl-4-(methylsulfonyl)-1-[(RS) -1-(2,4,6-triisopropylphenyl)ethoxy]pent-2-en-1-yl}cyclopentanone ((±)-10) and (±)-(2RS)-2{(1RS,2Z)-2-methyl-4-[(SR)-methylsulfonyl]-1-[(SR)-1 -(2,4,6-triisopropylphenyl)ethoxy]pent-2-en-1-yl}cyclopentanone ((±)-11). Similarly, enantiomerically pure dienyl ether (-)-(1S)-4a reacted with 1-(trimethylsilyloxy)cyclohexene (12) to give a 14.1:1 mixture of (-)-(2S)-2-{(1S,2Z,4R)-2-methyl-4-(methylsulfonyl)-1-[(S)-1-(2,4, 6-triisopropylphenyl)ethoxy]pent-2-enyl}cyclohexanone ((-)-13a) and its diastereoisomer 14a with (1S,2R,4R) or (1R,2S,4S) configuration. Structures of (±)-10, (±)-11, and (-)-13a were established by single-crystal X-ray crystallography. Poor diastereoselectivities were observed with the (E,E)-2-methylpenta-1,3-diene-1-ylethers (+)-4b and (-)-4c bearing (1S)-1-phenylethyl and (1S)-1-(pentafluorophenyl)ethyl groups instead of the Greene's auxiliary ((1S)-(2,4,6-triisopropylphenyl)ethyl group). The results demonstrate that high α/β-syn and asymmetric induction (due to the chiral auxiliary) can be obtained in the four-component syntheses of the β-alkoxy ketones. The method generates enantiomerically pure polyfunctional methyl sulfones bearing three chiral centers on C-atoms and one (Z)-alkene moiety.

Full text of DOI:10.1002/1522-2675(200206)85:6<1674::AID-HLCA1674>3.0.CO;2-2

1674
Helvetica Chimica Acta Vol. 85 (2002)
One-Pot, Asymmetric and Diastereoselective Four-Component Synthesis
of Polyfunctional (Z)-Alkenyl Methyl Sulfones with Three Stereogenic
Centers
by Vera Narkevitch1) and Pierre Vogel*
¬
¬ ¬
Institut des Sciences Moleculaires de l×Ecole Polytechnique Federale de Lausanne, BCH,
CH-1015 Lausanne-Ecublens
and Kurt Schenk
¬
Institut de Cristallographie, BSP, Universite de Lausanne, CH-1015 Lausanne-Dorigny
The reaction of 1-(trimethylsilyloxy)cyclopentene (9) with (Æ)-1,3,5-triisopropyl-2-(1-(RS)-{[(1E)-2-
methylpenta-1,3-dienyl]oxy}ethyl)benzene ((Æ)-4a) in SO2/CH2Cl2 containing (CF3SO2)2NH, followed by
treatment with Bu4NF and MeI gave a 3.0 :1 mixture of (Æ)-(2RS)-2{(1RS,2Z,4SR)-2-methyl-4-(methylsulfon-
yl)-1-[(RS)-1-(2,4,6-triisopropylphenyl)ethoxy]pent-2-en-1-yl}cyclopentanone ((Æ)-10) and (Æ)-(2RS)-2-
{(1RS,2Z)-2-methyl-4-[(SR)-methylsulfonyl]-1-[(SR)-1-(2,4,6-triisopropylphenyl)ethoxy]pent-2-en-1-yl}cyclo-
pentanone ((Æ)-11). Similarly, enantiomerically pure dienyl ether (À)-(1S)-4a reacted with 1-(trimethylsilyloxy)-
cyclohexene (12) to give a 14.1:1 mixture of (À)-(2S)-2-{(1S,2Z,4R)-2-methyl-4-(methylsulfonyl)-1-[(S)-1-
(2,4,6-triisopropylphenyl)ethoxy]pent-2-enyl}cyclohexanone ((À)-13a) and its diastereoisomer 14a with
(1S,2R,4R) or (1R,2S,4S) configuration. Structures of (Æ)-10, (Æ)-11, and (À)-13a were established by single-
crystal X-ray crystallography. Poor diastereoselectivities were observed with the (E,E)-2-methylpenta-1,3-
diene-1-ylethers (‡)-4b and (À)-4c bearing (1S)-1-phenylethyl and (1S)-1-(pentafluorophenyl)ethyl groups
instead of the Greene×s auxiliary ((1S)-(2,4,6-triisopropylphenyl)ethyl group). The results demonstrate that high
a/b-syn and asymmetric induction (due to the chiral auxiliary) can be obtained in the four-component syntheses
of the b-alkoxy ketones. The method generates enantiomerically pure polyfunctional methyl sulfones bearing
three chiral centers on C-atoms and one (Z)-alkene moiety.
Introduction. We have found a new CÀC bond-forming reaction that condenses
enyl silyl ethers (e.g., 1 and 2) with butadien-1-yl ethers (e.g., 3 and 4), SO2, and C-
electrophiles (e.g., MeI) to generate polyfunctional sulfones (e.g., 6 8, Scheme 1) in a
one-pot reaction [1 3]. The process is believed to involve a cascade of reactions
starting with the hetero-Diels-Alder addition of SO2 to the 1,3-dienyl ether, giving the
corresponding 3,6-dihydro-1,2-oxathiin-2-oxides (sultines) [4] in a reversible fashion.
In the presence of Lewis or protic acid catalysts, the intermediate sultines are ionized to
zwitterionic intermediates containing (Z)-allylic cation moieties, which add to the enyl
silyl ethers (oxyallylation) to give silyl sulfonates of type 5 that can be alkylated or
allylated in situ [3], providing the corresponding sulfones. An asymmetric version of
this reaction based on enantiomerically pure 1,3-dien-1-yl ethers such as 3 and 4
(Scheme 1) has been presented [5][6]. With dienyl ethers of type 4, the reaction is
highly b/e-unlike stereoselective. The reactions of enyl silyl ether 2 with dienyl ethers of
type 4 generate sulfones containing three stereogenic centers, the a/b-diastereoselec-
1
)
Current address: Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.

Helvetica Chimica Acta Vol. 85 (2002)
1675
tivity being modest [6]. The best asymmetric inductions were observed with reactions
involving dienyl ethers 3 and 4 bearing Greene×s chiral auxiliary [7]. With the goal to
improve the a/b-diastereoselectivity of our one-pot, four-component synthesis of b-
alkoxyketones we have now explored the reactions of cyclic enyl silyl ethers with dienyl
ethers of type 4. We report our preliminary results for the enyl trimethylsilyl ethers
derived from cyclopentanone and cyclohexanone and show that high a/b-syn
diastereoselectivity can be realized. It depends on the nature of the enyl silyl ethers
and of the chiral benzyloxy group in dienyl ethers 4. After acidic cleavage of the chiral
auxiliaries, enantiomerically pure b-hydroxy ketones can be obtained.
Scheme 1
Results. A 1:6 mixture of racemic dienyl ether (Æ-4a (derived from Greene×s
racemic auxiliary) and enyl silyl ether 9 (derived from cyclopentanone [8]) was allowed
to react with an excess of SO2 in the presence of (F3CSO2)2NH (À100 to À788). After
SO2 evaporation at low temperature and work-up with Bu4NF and an excess of MeI in
THF, a 3.0 :1 mixture of methyl sulfones (Æ)-10 and (Æ)-11 was obtained. Column
chromatography provided (Æ)-10 and (Æ)-11 in 52 and 19% yields, respectively
(Scheme 2). Their structures were established by single-crystal X-ray crystallography
(Figs. 1 and 2). Both b-alkoxy ketones (Æ)-10 and (Æ)-11 have the a/b-syn relative
configuration (C(1'), C(2) like). As for the other cases of oxyallylation with dienyl

1676
Helvetica Chimica Acta Vol. 85 (2002)
Scheme 2
Fig. 1. ORTEP [9] Representation of major b-alkoxy ketone (Æ)-10, showing heary atoms at the 50% probability
level2)
ethers 3 and 4 bearing Greene×s chiral auxiliary, the major product (Æ)-10 has a like
relative configuration at the benzylic C-atom C(1'') and the aldol C-atom C(1').
Although only modest asymmetric induction is obtained in the oxyallylation of 9, high
a/b-syn diastereoselectivity is realized.
Under similar conditions a 1:3 mixture of enantiomerically pure diene (À)-4a
(derived from Greene×s (S)-configured auxiliary [6]) and enyl silyl ether 12 (derived
from cyclohexanone [8]) led to 14.1:1 mixture of b-alkoxy ketones (À)-13a and 14a in
93% yield. The pure major ketone (À)-13a could be isolated by flash chromatography,
and its structure was also established by single-crystal X-ray crystallography (Fig. 3).
As for the oxyallylation of 9, the reaction of enyl silyl ether 12 with dienyl ether (À)-4a
is also a/b-syn stereoselective (Scheme 3). Acidic cleavage of the chiral benzylic
auxiliary of a 2.4 :1 mixture of (À)-13a and 14a (CF3COOH, CDCl3 [10]) gave a 2.5 :1
mixture of the b-hydroxy ketones 15 and 16, thus demonstrating that the minor
compound 14a has a a/b-anti relative configuration. The absolute configurations of 14a
and 16 have not been determined.
2) For reasons of commodity, atom numbering does not follow the IUPAC rules.

Helvetica Chimica Acta Vol. 85 (2002)
1677
Fig. 2. ORTEP [9] Representation of minor b-alkoxy ketone (Æ)-11, showing heary atoms at the 50% probability
level2)
Fig. 3. ORTEP [9] Representation of major b-alkoxy ketone (Æ)-13a, showing heavy atoms at the 50%
probability level2)
Although satisfactory diastereoselectivity was observed for the oxyallylation 12 ‡
(À)-4a ‡ SO2 ‡ MeI ! (À)-13a, we explored whether it could be improved or modified
by exchange of the Greene×s chiral auxiliary by other benzylic (1S)-configured
auxiliaries. We prepared dienyl ethers (‡)-4b and (À)-4c as shown in Scheme 3 [11].
Substitution of the EtO group of (E)-3-ethoxy-2-methylprop-2-enal (17) with (À)-(S)-
1-phenylethoxy and (À)-(S)-1-(pentafluorophenyl)ethoxy groups [6] gave aldehydes
(‡)-18b and (À)-18c, respectively. Wittig olefination with (EtPPh3)Br and (i-Pr)2NLi in
THF provided (‡)-4b and (À)-4c, respectively, in good yield.
The oxyallylation of enyl silyl ether 12 with dienyl ether (‡)-4b, SO2, and MeI
provided a 1.6 :1 mixture of (À)-13b and (À)-14b in 48% yield (considering the

1678
Helvetica Chimica Acta Vol. 85 (2002)
Scheme 3
OEt
OR*
OR*
Me
O
Me
O
Me
EtP+Ph3Br–
R*OH
(i-Pr)2NLi, THF
H
H
17
18
(–)-4a R* = Greene's (1S)-auxiliary (a)
(+)-4b R* = (1S)-HC(Me)Ph (b)
(–)-4c R* = (1S)-HC(Me)C6F5 (c)
SO2Me
SO2Me
OSiMe3
O
R*O
O
R*O
1) + 4, SO2, (F3CSO2)NH
+
2) Bu4NF, THF, MeI
yield
12
ratio
R* = a
R* = b
R* = c
(–)-13a
(–)-13b
(–)-13c
14a
(–)-14b
(–)-14c
14.1:1
1.6:1
1.2:1
93%
48%
19%
CF3COOH
CDCl3
R* = H
15
16
recovery of the starting dienyl ether). These products could be separated by column
chromatography. Under similar conditions, reaction 12 ‡ (À)-4c ‡ SO2 ‡ MeI was even
less satisfactory, as it led to a 1.2 :1 mixture of (À)-13c and (À)-14c in mediocre yield
(19%). Acidic cleavage of the chiral benzylic moieties of (À)-13b and (À)-13c provided
b-hydroxy ketone 15, whereas (À)-14b and (À)-14c gave its a/b-anti isomer 16
(absolute configurations not known).
Discussion. The diastereoselectivity (1'S,1''S) vs. (1'R,1''S) induced by the benzylic
chiral auxiliary arises from the facial stereoselectivity of the hetero-Diels-Alder
addition of SO2 activated by the acid promotor (F3CSO2)2NH as shown in Scheme 4.
The intermediate sultine equilibrates with dienyl ether‡ SO2 and with the correspond-
ing zwitterions 19. If the latter is not quenched rapidly by reaction with the enyl silyl
ether, both modes of hetero-Diels-Alder reaction compete and lead to a decrease in
(1',1'')-diastereoselectivity, as zwitterions 19' form also and react with the enyl silyl
ether [6]. The a/b-syn vs. a/b-anti diastereoselectivity of the oxyallylation is governed
by the orientation of the attacking enyl silyl ether. In the case of reactions of 12 with
dienyl ethers (À)-4a, (‡)-4b, and (À)-4c, reaction paths involving orientations of type
20 are preferred for steric reasons (Fig. 4), as for Mukaiyama cross-aldol reactions [12]
(open transition state [13]). The preference for the orientation of type 21 or 21'
depends also on the nature of the enyl silyl ether: it is higher for the five-membered-
ring than for the six-membered-ring enyl silyl ether. Very important is the nature of the
substituents at C(2) and C(6) of the phenyl ring of the chiral benzyl auxiliary. For small
substituents (H, F) as with dienyl ethers (‡)-4b and (À)-4c, orientations of type 21 or
21' compete with reaction paths involving orientations of type 20. With large

Helvetica Chimica Acta Vol. 85 (2002)
1679
Scheme 4
enyl silyl ether
SO2CF3
Me
O
Me
Ar
H
SO2·HN
Ar
O
SO2CF3
Me
Me
H
H
H
1''
1''
O
(1'S,1''S)
(1'R,1''S)
S
A
H
H
Diels-Alder and
Me
Me
O
ionization
19 (preferred)
4
SO2CF3
SO2·HN
O
O
A
SO2CF3
Me
O
S
Ar
Diels-Alder and
Me
H
ionization
H
H
Me
enyl silyl ether
19'
Fig. 4. Orientations involved in different reaction paths
substituents at C(2) and C(6), such as the i-Pr groups of Greene×s auxiliary (dienyl ether
(À)-4a), orientations 21 or 21' are more hindered than 20 for steric reasons. Thus, this
explains the difference in a/b-syn vs. a/b-anti diastereoselectivity of the reaction of enyl
silyl ether 12 with enantiomerically pure dienyl ethers (À)-4a, (‡)-4b, and (À)-4c.
Conclusions. The four-component synthesis of b-alkoxy ketones that condenses
enyl silyl ethers, 1,3-dien-1-yl ethers, SO2, and MeI can be highly a/b-syn diaster-
eoselective for cyclic enyl silyl ethers such as those derived from cyclopentanone and
cyclohexanone. With the 1-arylethyl (E,E)-2-methylpenta-1,3-dienyl ether bearing
Greene×s chiral auxiliary (4a), good diastereoselectivity induced by the chiral auxiliary
is observed. The results can be interpreted in terms of steric factors, as for the
Mukaiyama cross-aldol reaction. Better yield and diastereoselectivity can be reached
by tuning the domino game that involves the chiral auxiliary attached as an 1-oxy-group
to the 1,3-diene and the shape of the enyl silyl ether.
¬
¬
We thank the Swiss National Science Foundation (Bern) and the Office Federal de l×Education et de la
¬
Science (European COST D13/010/00) for financial support. We are grateful also to M. Rey and F. Sepulveda for
their technical help.

1680
Helvetica Chimica Acta Vol. 85 (2002)
Experimental Part
General. See [6][14].
(‡)-{(S)-1-[((E,E)-2-Methylpenta-1,3-dien-1-yl)oxy]ethyl}benzene ((‡)-4b). (i-Pr)2NH (3.3 ml, 20 mmol)
in anh. THF (30 ml) was added dropwise to a stirred 1.6m soln. of BuLi in hexane (13.8 ml, 20 mmol) at À 788.
The mixture was then allowed to warm to 08 and was stirred 1 h at this temp. (EtPPh3)Br (6.75 g, 18.1 mmol) was
added portionwise under stirring, and the mixture was stirred at 208 for 1 h. Crude ((‡)-(E)-2-methyl-3-((S)-1-
phenylethoxy)prop-2-enal) (‡)-18b), prepared by transetherification of (E)-3-ethoxy-2-methylprop-2-enal
(17) with (S)-1-phenylethanol (2.02 g, 16.6 mmol) [11][12], was added at 08, and the mixture stirred at 08 for 2 h.
After addition of ice-cold H2O (100 ml), the mixture was extracted with light petroleum ether (3 Â 50 ml). The
combined extracts were dried (MgSO4), and the solvent evaporated in vacuo. The residue was dissolved in light
petroleum ether. The precipitate (Ph3PO) was filtered off, and the solvent evaporated in vacuo to give (‡)-4b as
25
25
25
a yellowish oil (3.83 g, quantitative). [a]D25 ˆ ‡10, [a] ˆ ‡11, [a] ˆ ‡14, [a] ˆ ‡36, (c ˆ 1.2, CHCl3). IR
578
546
436
(film): 2980, 1650, 1450, 1370, 1165, 1070, 1025, 955, 840, 760, 700. 1H-NMR (400 MHz, CDCl3): 7.70 7.29
(m, 5 arom. H); 6.08 (q, 4J('',2'') ˆ 1.2, HÀC(1'')); 5.87 (dq, 3J(3'',4'') ˆ 15.4, 4J(3'',5'') ˆ 1.5, HÀC(3'')); 5.45
(dq, 3J(3'',4'') ˆ 15.4, 3J(4'',5'') ˆ 6.7, HÀC(4'')); 4.78 (q, 3J(1',2') ˆ 6.5, HÀC(1')); 1.77 (d, 4J(1'',2'') ˆ 1.2,
MeÀC(2'')); 1.73 (dd, 3J(4'',5'') ˆ 6.7, 4J(3'',5'') ˆ 1.5, H3C(5'')); 1.57 (d, 3J(1',2') ˆ 6.5, Me(2')). 13C-NMR
(100.6 MHz, CDCl3): 144.3 (d, 1J(C,H) ˆ 177, C(1'')); 143.2 (s, arom. C); 130.9 (d, 1J(C,H) ˆ 149, C(3''));
128.4 (d, 1J(C,H) ˆ 159, 2 arom. C); 125.9 (d, 1J(C,H) ˆ 162, 2 arom. C); 119.5 (d, 1J(C,H) ˆ 150, C(4'')); 114.9
(s, C(2'')); 79.7 (d, 1J(C,H) ˆ 147, C(1')); 23.8 (q, 1J(C,H) ˆ 129, C(2')); 18.3 (q, 1J(C,H) ˆ 126, C(5'')); 9.8
.
‡
(q, 1J(C,H) ˆ 130, MeÀC(2'')). CI-MS (NH3): 220 (32, [M ‡ 18] ), 203 (100, [M ‡ 1] ), 202 (31, M ), 139 (19),
122 (71), 105 (82), 98 (45), 77 (12). Anal. calc. for C12F5H9O9 (328.54): C83.12, H 8.97; found: C 83.14, H 9.02.
(À)-(E)-2-Methyl-3-[(S)-1-(pentafluorophenyl)ethoxy]prop-2-enal ((À)-18c). A mixture of 17 (1.02 ml,
8.5 mmol), (À)-(S)-1-(pentafluorophenyl)ethanol [6] (1.75 g, 8.22 mmol), and TsOH (16 mg) was stirred at 208
for 16 h under vacuum (1 Torr) to evacuate EtOH formed in the reaction. The residue was purified by FC (SiO2,
‡
‡
CH2Cl2, Rf ((À)-18c) ˆ 0.27) to give (À)-18c as a colorless oil (1.74 g, 75%). [a]2D5 ˆ À8.2, [a] ˆ À8.5, [a]
ˆ
25
25
578
546
25
À9.5, [a] ˆ À12.8 (c ˆ 1.1, CHCl3). IR (film): 2990, 1645, 1505, 1455, 1370, 1305, 1215, 1150, 1080, 1045, 975,
436
870. 1H-NMR (400 MHz, CDCl3): 9.23 (s, HÀC(1)); 6.97 (q, 4J(2,3) ˆ 1.1, HÀC(3)); 5.49 (q, 3J(1',2') ˆ 6.8,
HÀC(1')); 1.82 (d, 3J(1',2') ˆ 6.8, Me(2')); 1.70 (d, 4J(2,3) ˆ 1.1, MeÀC(2)). 13C-NMR (100.6 MHz, CDCl3):
191.5 (d, 1J(C,H) ˆ 170, C(1)); 164.6 (d, 1J(C,H) ˆ 176, C(3)); 144.6 (d, 1J(C,F) ˆ 251, 2 arom. C); 141.5
(d, 1J(C,F) ˆ 255, arom. C); 137.7 (d, 1J(C,F) ˆ 251, 2 arom. C); 121.9 (s, C(2)); 113.8 (s, arom. C); 73.3
(d, 1J(C,H) ˆ 149, C(1')); 20.4 (q, 1J(C,H) ˆ 130, C(2')); 6.3 (q, 1J(C,H) ˆ 126, MeÀC(2)). CI-MS (NH3): 298
.
‡
‡
‡
(99, [M ‡ 18] ), 281 (100, [M ‡ 1] ), 280 (2, M ), 229 (2), 212 (17), 195 (30), 175 (7), 145 (12), 104 (10), 87
(25).
(À)-1,2,3,4,5-Pentafluoro-6-{(S)-1-[((1E,Z,3E)-2-methylpenta-1,3-dien-1-yl)oxy]ethyl}benzene ((À)-4c).
(i-Pr)2NH (1.2 ml, 7.25 mmol) in anh. THF (20 ml) was added dropwise to a stirred soln. of 1.6m BuLi in
hexane (5 ml, 7.25 mmol) at À788. After stirring at 08 for 2.5 h, (EtPPh3)Br (2.44 g, 6.56 mmol) was added, and
the mixture stirred at 208 for 1 h. Then, (À)-18c (1.7 g) was added to the mixture at 08. After stirring at 08 for 2 h,
ice-cold H2O (100 ml) was added, and the mixture extracted with light petroleum ether (3 Â 50 ml). The
combined extracts were dried (MgSO4), and the solvent was evaporated in vacuo. The residue was purified by
FC (SiO2, CH2Cl2/light petroleum ether 1 :2, Rf ((À)-4c) ˆ 0.59) to give (À)4c as a colorless oil, 5 :1 mixture of
(1E)-and (1 Z)-isomers (0.626 g, 36%).
(Æ)-(2RS)-2-{(1RS,2Z,4SR)-2-Methyl-4-(methylsulfonyl)-1-[(RS)-1-(2,4,6-triisopropylphenyl)ethoxy]-
pent-2-en-1-yl}cyclopentanone ((Æ)-10) and (Æ)-(2RS,2Z)-2-{(1RS,2Z,4SR)-2-Methyl-4-(methylsulfonyl)-1-
[(SR)-1-(2,4,6-triisopropylphenyl)ethoxy]pent-2-en-1-yl}cyclopentanone ((Æ)-11).
A
0.5m soln. of
(F3CSO2)2NH in anh. CH2Cl2 (60 ml, 0.03 mmol) was degassed (freeze/thaw cycles) on the vac. line (two
necked flask). Dry SO2 (basic alumina, Merck, act. I) was condensed at À1968 (0.32 0.64 g, 5 10 mmol). The
flask was allowed to warm to À788, and the mixture was stirred for 30 min. After cooling to À1008, (Æ)-1,3,5-
triisopropyl-2-{(RS)-1-[((E,E)-2-methylpenta-1,3-dien-1-yl)oxy]ethyl}benzene ((Æ)-4a [6][7]; 0.052 g,
0.16 mmol) in anh. CH2Cl2 (0.5 ml) and 1-(trimethylsilyloxy)cyclopentene (9; 0.15 ml, 0.9 mmol) [8] were
added simultaneously. After stirring at À858 for 2.5 h and then at À788 for 2.5 h, the solvents were evaporated
in vacuo at À788. 1m Bu4NF in THF (1.5 ml, 1.5 mmol) and MeI (0.3 ml, 5 mmol) were added under Ar, and the
mixture was allowed to warm gradually to 208 overnight. H2O (15 ml) was added, and the mixture extracted with
CH2Cl2 (5 Â 10 ml). The combined extracts were dried (MgSO4), and the solvent was evaporated in vacuo. The
residue was purified by CC (SiO2, AcOEt/light petroleum ether 1 :3, Rf ((Æ)-10) ˆ 0.12, Rf ((Æ)-11) ˆ 0.07) to
give (Æ)-10 (39 mg, 52%) and (Æ)-11 (14 mg, 19%), which were crystallized from light petroleum ether/Et2O.

Helvetica Chimica Acta Vol. 85 (2002)
1681
Data of (Æ)-10. Colorless crystals (see Table 1). M.p. 170 1728. UV (MeCN): 249 (1200), 222 (1300). IR
1
(KBr): 2965, 2925, 1735, 1610, 1455, 1370, 1325, 1300, 1140, 1070, 1025, 1005, 960, 880, 770, 540, 505. H-NMR
(400 MHz, CDCl3): 7.00 6.91 (m, 2 arom. H); 5.30 (dq, 3J(3',4') ˆ 10.6, 4J(2',3') ˆ 1.1, HÀC(3')); 5.05
(q, 3J(1'',2'') ˆ 6.7, HÀC(1'')); 4.79 (d, 3J(1',2) ˆ 2.8, HÀC(1')); 4.16 (dq, 3J(3',4') ˆ 10.6, 3J(4',5') ˆ 6.7,
HÀC(4')); 3.84, 3.11 (2 sept., 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, 2 Me2CHÀAr); 2.92 (s, MeSO2); 2.84
(sept., 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, Me2CHÀAr); 2.07 1.66 (m, HÀC(2), H2C(3), H2C(4), H2C(5));
1.95 (d, 4J(2',3') ˆ 1.1, MeÀC(2')); 1.46 (d, 3J(4',5') ˆ 3J(1'',2'') ˆ 6.7, Me(5'), Me(2'')); 1.29 1.16
(m, 2 Me2CHÀAr); 1.27 (d, 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, (Me2CHÀAr). 13C-NMR (100.6 MHz,
CDCl3): 218.3 (s, C(1)); 147.9, 147.0, 146.3, 144.5 (4s, 3 arom. C, C(2')); 134.4 (s, arom. C); 122.7, 120.4
(2d, 1J(C,H) ˆ 152, 153, 2 arom. C); 118.2 (d, 1J(C,H) ˆ 158, C(3')); 77.0 (d, C(1')); 76.6 (d, C(1'')); 57.5
(d, 1J(C,H) ˆ 137, C(4')); 55.7 (d, 1J(C,H) ˆ 124, C(2)); 38.1 (t, 1J(C,H) ˆ 131, C(5)); 37.8 (q, 1J(C,H) ˆ 138,
MeSO2); 33.9, 29.05, 29.00 (3d, 1J(C,H) ˆ 127, 129, 129, 3 Me2CHÀAr); 25.4, 24.6, 24.4, 23.91, 23.86
(5q, 1J(C,H) ˆ 125, 3 Me2CHÀAr); 24.5, 20.5 (2t, 1J(C,H) ˆ 127, C(3), C(4)); 22.0 (q, 1J(C,H) ˆ 127, C(2''));
‡
21.0 (q, 1J(C,H) ˆ 129, MeÀC(2')); 14.7 (q, 1J(C,H) ˆ 130, C(5')). CI-MS (NH3): 508 (0.2, [M ‡ 18] ),475 (2),
230 (100), 215 (46), 163 (43), 91 (13). Anal. calc. for C29H46O4S (490.74): C 70.98, H 9.45, S 6.53; found: C 70.96,
H 9.38, S 6.45.
Table 1. Crystal Data and Structure Refinement of (Æ)-10
Empirical formula
Mr
Temperature [K]
Wavelength [ä]
Crystal system
Space group
Unit-cell dimensions a [ä]
C29H46O4S
490.72
293(2)
0.71069
monoclinic
Cc
45.646(5)
10.970(5)
11.982(5)
97.224(5)
5952(4)
8
F(000)
Crystal size [mm]
q Range [8]
2144
n/a
3.60 to 25.00
28763
Reflect. collected
Independent reflect.
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices (I > 2s(I))
R indices (all data)
Weights
9991
Full-matrix least-squares on F2
9991/2/615
b [ä]
c [ä]
b [8]
V [ä3]
1.069
R1 ˆ 0.0722, w2R2 ˆ 0.1798
R1 ˆ 0.0911, w2R2 ˆ 0.1931
[s2(F2o ‡ (0.0922 ¥ P)2 ‡ 7.01 ¥ P]À1
(Max(F2o, 0) ‡ 2 ¥ F2c )/3
0.226 and À0.249
Z
where P ˆ
Density calc. [g cmÀ3
]
1.095
0.138
Largest difference peak
Absorption coeff. [mmÀ1
]
and hole [e ¥ AÀ3
]
Data of (Æ)-11: Colorless crystals (see Table 2). M.p. 128 1308 (m, (MeOH). UV (MeCN): 287 (2800),
215 (13000). IR (KBr): 2960, 2930, 1735, 1460, 1380, 1310, 1140, 1105, 1070, 1030, 960, 930, 875, 765, 650.
1H-NMR (400 MHz, CDCl3): 7.00 6.91 (m, 2 arom. H); 5.33 (dq, 3J(3',4') ˆ 10.6, 4J(2',3') ˆ 1.1, HÀC(3')); 4.92
(q, 3J(1'',2'') ˆ 6.5, HÀC(1'')); 4.86 (d, 3J(1',2) ˆ 3.5, HÀC(1')); 4.05 (dq, 3J(3',4') ˆ 10.6, 3J(4',5') ˆ 6.8,
HÀC(4')); 3.71, 3.09, 2.83 (3sept., 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, 3 Me2CHÀAr); 2.74 (s, MeSO2);
2.42 1.75 (m, HÀC(2), H2C(3), H2C(4), H2C(5)); 1.66 (d, 4J(2',3') ˆ 1.1, MeÀC(2')); 1.43 (d, 3J(1'',2'') ˆ 6.5,
Me(2'')); 1.41 (d, 3J(4',5') ˆ 6.8, Me(5')); 1.24 1.12 (m, 2 Me2CHÀAr); 1.24 (d, 3J(Me2CHÀAr, Me2CHÀAr) ˆ
6.9, Me2CHÀAr). 13C-NMR (100.6 MHz, CDCl3): 218.4 (s, C(1)); 148.1, 147.1, 145.3, 144.7 (4s, 3 arom. C, C(2'));
134.5 (s, arom. C); 122.9, 120.5 (2d, 1J(C,H) ˆ 152, 153, 2 arom. C); 121.1 (d, 1J(C,H) ˆ 160, C(3')); 73.1
(d, 1J(C,H) ˆ 140, C(1')); 71.1 (d, 1J(C,H) ˆ 140, C(1'')); 57.2 (d, 1J(C,H) ˆ 137, C(4')); 54.3 (d, 1J(C,H) ˆ 123,
C(2)); 38.5 (t, 1J(C,H) ˆ 132, C(5)); 37.2 (q, 1J(C,H) ˆ 138, MeSO2); 33.9, 29.03, 28.97 (3d, 1J(C,H) ˆ 126, 128,
128, 3 Me2CHÀAr); 25.5, 25.0, 24.7, 23.93, 23.87 (5q, 1J(C,H) ˆ 125, 3 Me2CHÀAr); 24.5, 20.9 (2t, 1J(C,H) ˆ
128, 134, C(3), C(4)); 20.7 (q, 1J(C,H) ˆ 126, C(2'')); 20.1 (q, 1J(C,H) ˆ 126, MeÀC(2')); 14.4 (q, 1J(C,H) ˆ 130,
‡
C(5')). CI-MS (NH3): 508 (100, [M ‡ 18] ), 475 (5), 335 (6), 231 (99), 215 (22), 163 (29), 91 (9). Anal. calc. for
C29H46O4S (490.74): C 70.98, H 9.45, S 6.53; found: C 70.82, H 9.40, S 6.57.
(À)-(2S)- and (2R)-2-{(1S,2Z,4R)-2-Methyl-4-(methylsulfonyl)-1-[(S)-1-(2,4,6-triisopropylphenyl)ethoxy]-
pent-2-en-1-yl}cyclohexanone ((À)-13a and 14a). As described for (Æ)-10 and (Æ)-11, with dienyl ether (À)-
4a [6] (50 mg, 0.152 mmol) and (trimethylsilyloxy)cyclohexene (12) (0.1 ml, 0.5 mmol). Purification by CC
(SiO2, AcOEt/light petroleum ether 1:3, Rf ((À)-13a) ˆ 0.28) gave as a first fraction pure (À)-13a (55 mg, 72%).

1682
Helvetica Chimica Acta Vol. 85 (2002)
Table 2. Crystal Data and Structure Refinement of (Æ)11
Empirical formula
Mr
C29H46O4S
490.72
Absorption coeff. [mmÀ1
F(000)
]
0.146
536
Temperature [K]
Wavelength [ä]
Crystal system
Space group
90(2)
Crystal size [mm]
q Range [8]
Index ranges
0.32 Â 0.2 Â 0.1
0.71073
triclinic
2.63 to 27.99
À 11 ꢀ h ꢀ 11, À15 ꢀ k ꢀ 14,
À20 ꢀ l ꢀ 19
≈
P1
Unit-cell dimensions a [ä]
8.875(2)
11.554(2)
15.292(3)
71.93(3)
74.20(3)
74.68(3)
1406.3(5)
2
Reflect. collected
Independent reflect.
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices (I > 2s(I))
R indices (all data)
Weights
13068
6040
b [ä]
c [ä]
a [8]
b [8]
g [8]
V [ä3]
Full-matrix least-squares on F2
6004/0/308
5.741
R1 ˆ 0.0460, w2R2 ˆ 0.0770
R1 ˆ 0.0590, wR2 ˆ 0.1943
[s2(F2o )]À1
0.367 and À0.469
Z
Density calc. [g cmÀ3
]
1.159
Largest difference peak
and hole [e ¥ AÀ3
]
A second fraction afforded a 2.4 :1 mixture of (À)-13a and 14a (16 mg, total yield: 93%). The crude mixture
1
containing a 14.1 :1 mixture of (À)-13a and 14a was examined by H-NMR spectroscopy.
Data of (À)-13a: Colorless crystals (see Table 3). M.p. 146 1488 (light petroleum ether/Et2O). [a]2D5 ˆ À94,
25
25
25
25
[a] ˆ À100, [a] ˆ À115, [a] ˆ À212, [a] ˆ À265 (c ˆ 2.5, CHCl3).UV (MeCN): 216 (15100). IR
578
546
436
405
(KBr): 2965, 2870, 1715, 1610, 1450, 1370, 1280, 1140, 1075, 1035, 965, 880, 775, 505. 1H-NMR (400 MHz,
CDCl3): 7.03 6.92 (m, 2 arom. H); 5.40 (dq, 3J(3',4') ˆ 10.8,4J(2',3') ˆ 1.3, HÀC(3')); 5.13 (q, 3J(1'',2'') ˆ 6.6,
HÀC(1'')); 4.50 (d, 3J(1',2) ˆ 7.9, HÀC(1)); 4.41 (dq, 3J(3',4') ˆ 10.8, 3J(4',5') ˆ 6.7, HÀC(4')); 3.82, 3.20, 2.86
(3sept., 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, 3 Me2CHÀAr); 2.89 (s, MeSO2); 2.63 1.67 (m, HÀC(2), H2C(3),
H2C(4), H2C(5), H2C(6)); 1.89 (d, 4J(2',3') ˆ 1.3, MeÀC(2')); 1.54 (d, 3J(4',5') ˆ 6.7, Me(5')); 1.49 (d, 3J(1'',2'') ˆ
6.6, Me(2'')); 1.26 1.17 (m, 2 Me2CHÀAr); 1.25 (d, 3J(Me2CHÀAr, Me2CHÀAr) ˆ 6.9, Me2CHÀAr).
13C-NMR (100.6 MHz, CDCl3): 211.8 (s, C(1)); 148.1, 146.9, 145.5, 144.3 (4s, 3 arom. C, C(2')); 134.8
(s, arom. C), 122.8, 120.3 (2d, 1J(C,H) ˆ 149, 153, 2 arom. C); 119.4 (d, 1J(C,H) ˆ 157, C(3')); 77.3
(d, 1J(C,H) ˆ 158, C(1')); 75.8 (d, 1J(C,H) ˆ 140, C(1'')); 58.5 (d, 1J(C,H) ˆ 140, C(4')); 56.2 (d, 1J(C,H) ˆ 128,
C(2)); 42.7 (t, 1J(C,H) ˆ 125, C(6)); 37.3 (q, 1J(C,H) ˆ 138, MeSO2); 33.8 (d, 1J(C,H) ˆ 126, Me2CHÀAr); 31.5,
28.5, 24.93 (3t, 1J(C,H) ˆ 133, 134, 134, C(3), C(4), C(5)); 29.0, 28.9 (2d, 1J(C,H) ˆ 123, 130, 2 Me2CHÀAr);
25.03, 24.97, 24.8, 24.2, 23.9 (5q, 1J(C,H) ˆ 124,
3
Me2CHÀAr); 22.9 (q, 1J(C,H) ˆ 129, C(2'')); 20.9
‡
(q, 1J(C,H) ˆ 128, MeÀC(2')); 15.5 (q, 1J(C,H) ˆ 130, C(5')). CI-MS (NH3): 522 (75, [M ‡ 18] ), 504 (2,
.
‡
M
), 480 (5), 425 (7), 381 (1), 274 (74), 248 (10), 231 (100), 177 (20), 149 (4), 91 (6). Anal. calc. for C30H48O4S
(504.77): C 71.39, H 9.58, S 6.35; found: C 71.48, H 9.60, S 6.32.
Data of 14a: 1H-NMR (400 MHz, CDCl3): 7.03 6.92 (m, 2 arom. H); 5.43 (dq, 3J(3',4') ˆ 10.8, 4J(2',3') ˆ
1.3, HÀC(3')); 5.25 (q, 3J(1'',2'') ˆ 6.7, HÀC(1'')); 4.70 (d, 3J(1',2) ˆ 8.0, HÀC(1')); 4.26 (dq, 3J(3',4') ˆ 10.8,
3J(4',5') ˆ 6.8, HÀC(4')); 3.72, 3.28 (2 br. s, 2 Me2CHÀAr); 2.89 (s, MeSO2); 2.86 (sept., 3J(Me2CHÀAr,
Me2CHÀAr) ˆ 6.8, Me2CHÀAr); 2.64 1.65 (m, HÀC(2), H2C(3), H2C(4), H2C(5), H2C(6)); 1.89
(d, 4J(2',3') ˆ 1.3, MeÀC(2')); 1.46, 1.35 (2d, 3J(4',5') ˆ 6.8, 3J(1'',2'') ˆ 6.7, Me(5'), Me(2'')); 1.26 1.17
(m, 3 Me2CHÀAr).
2.5 :1 Mixture of (2S)- and (2R)-2-[(1S,2Z,4R)-1-Hydroxy-2-methyl-4-(methylsulfonyl)pent-2-en-1-yl]cy-
clohexanone or (2S)-2-[(1R,2Z,4S)-1-Hydroxy-2-methyl-4-(methylsulfonyl)pent-2-en-1-yl]cyclohexanone (15
and 16). A 2.4 :1 mixture of (À)-13a and 14a (16 mg, 0.032 mmol), CDCl3 (0.35 ml), and CF3COOH (40 ml,
0.54 mmol) was stirred at 258 for 25 min. After neutralization with sat. aq. NaHCO3 (10 ml), the mixture was
extracted with CH2Cl2 (3 Â 10 ml). The combined org. extracts were dried (MgSO4), the solvent was
evaporated, and the residue purified by FC (SiO2, AcOEt/CH2Cl2 1:1) to give a 2.5 :1 mixture of 15 and 16 as a
colorless oil (4 mg, 49%). IR (film): 3500, 2935, 2865, 1715, 1650, 1455, 1415, 1380, 1295, 1135, 1030, 955, 765,
.
‡
735. CI-MS (NH3): 274 (1, M ), 259 (1), 248 (4), 231 (100), 215 (12), 191 (9), 149 (5), 109 (11), 95 (19). Anal.
calc. for C13H22O4S (274.37): C 56.91, H 8.08; found: C 56.82, H 8.0.

Helvetica Chimica Acta Vol. 85 (2002)
1683
Table 3. Crystal Data and Structure Refinement of (À)-13a
≈
Empirical formula
Mr
C30H48O4S
504.74
293(2)
0.71073
monoclinic
P21
Morphology Pinacoids
Pedions
{101}, {101}
(110), (011)
(010)
3.08 to 27.99
13 ꢀ h ꢀ 13, À12 ꢀ k ꢀ 11,
À20 ꢀ l ꢀ 21
13656
≈
Temperature [K]
Wavelength [ä]
Crystal system
Space group
Unit-cell dimensions a [ä]
b [ä]
Fracture plane
q Range [8]
Index ranges
10.037(2)
9.408(2)
15.971(3)
103.03(3)
Reflect. collected
Independent reflect.
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices (I > 2s(I))
R indices (all data)
Weights
6306
c [ä]
b [8]
Full-matrix least-squares on F2
6306/1/316
V [ä3] 1469.2(5)
5.423
Z
2
R1 ˆ 0.0426, wR2 ˆ 0.0744
R1 ˆ 0.0452, wR2 ˆ 0.0746
[s2(F2o )]À1
Density calc. [g cmÀ3
Absorption coeff. [mmÀ1
F(000)
]
1.141
0.141
552
]
Absolute structure parameter 0.11(6)
0.225 and À0.223
Crystal size [mm]
0.7 Â 0.5 Â 0.2 Largest difference peak
and hole [e ¥ AÀ3
]
Data of 15: 1H-NMR (400 MHz, CDCl3): 5.41 (dq, 3J(3',4') ˆ 10.8, 4J(2',3') ˆ 1.4, HÀC(3')); 4.69
(dd, 3J(1',2) ˆ 9.3, 3J(1',HOÀC(1')) ˆ 2.0, HÀC(1')); 4.06 (dq, 3J(3',4') ˆ 10.8, 3J(4',5') ˆ 6.8, HÀC(4')); 3.68
(d, 3J(HOÀC(1'),1') ˆ 2.0, HOÀC(1')); 2.91 (s, MeSO2); 2.60 1.65 (m, HÀC(2), H2C(3), H2C(4), H2C(5),
H2C(6)); 1.83 (d, 4J(2',3') ˆ 1.4, MeÀC(2')); 1.44 (d, 3J(4',5') ˆ 6.8, Me(5')). 13C-NMR (100.6 MHz, CDCl3):
216.0 (s, C(1)); 141.2 (s, C(2')); 123.8 (d, 1J(C,H) ˆ 157, C(3')); 69.6 (d, 1J(C,H) ˆ 141, C(1)); 57.2 (d, 1J(C,H) ˆ
137, C(4')); 53.1 (d, 1J(C,H) ˆ 128, C(2)); 42.5 (t, 1J(C,H) ˆ 128, C(6)); 38.2 (q, 1J(C,H) ˆ 138, MeSO2); 29.9,
27.5, 24.7(3t, 1J(C,H) ˆ 129, C(3), C(4), C(5)); 18.5 (q, 1J(C,H) ˆ 128, MeÀC(2)); 12.6 (q, 1J(C,H) ˆ 129,
C(5')).
Data of 16: 1H-NMR (400 MHz, CDCl3): 5.16 (dq, 3J(3',4') ˆ 9.8, 4J(2',3') ˆ 1.4, HÀC(3')); 4.70
(dd, 3J(1',HOÀC(1')) ˆ 2.3, HÀC(1')); 4.23 (dq, 3J(3',4') ˆ 9.8, 3J(4',5') ˆ 6.9, HÀC(4')); 2.86 (s, MeSO2);
2.76 1.65 (m, HÀC(2), H2C(3), H2C(4), H2C(5), H2C(6)); 1.75 (d, 4J(2',3') ˆ 1.4, MeÀC(2')); 1.57
(d, 3J(4',5') ˆ 6.9, Me(5')). 13C-NMR (100.6 MHz, CDCl3): 215.1 (s, C(1)); 145.5 (s, C(2')); 119.8 (d, 1J(C,H) ˆ
151, C(3')); 69.1 (d, 1J(C,H) ˆ 145, C(1')); 58.0 (d, 1J(C,H) ˆ 141, C(4')); 53.5 (d, 1J(C,H) ˆ 127, C(2)); 42.8
(t, 1J(C,H) ˆ 128, C(6)); 37.0 (q, 1J(C,H) ˆ 138, MeSO2); 30.7, 28.7, 25.0 (3t, 1J(C,H) ˆ 129, C(3), C(4), C(5));
19.2 (q, 1J(C,H) ˆ 128, MeÀC(2')); 15.3 (q, 1J(C,H) ˆ 129, C(5')).
(À)-(2S)- and (2R)-2-[(1S,2Z,4R)-2-Methyl-4-(methylsulfonyl)-1-((S)-1-phenylethoxy)pent-2-en-1-yl]cy-
clohexanone ((À)-13b and (À)-14b)3). As described for (À)-13a with (‡)-4b (148 mg, 0.73 mmol) and 12
(0.25 ml, 1.25 mmol). CC (SiO2, AcOEt/light petroleum ether 1 :3, Rf ((À)-13b) ˆ 0.15, Rf ((À)-14b) ˆ 0.11)
afforded (‡)-4b (29 mg, 0.14 mmol), (À)-13b (55 mg, 20%), and (À)-14b (33 mg, 12%) and a mixture of (À)-
13b and (À)-14b (18 mg, 7%). 1H-NMR of the crude product showed a 1.6 :1 mixture of (À)-13b and (À)-14b.
25
25
25
Data of (À)-13b: Colorless oil. [a]2D5 ˆ À58, [a] ˆ À60, [a] ˆ À68, [a] ˆ À124 (c ˆ 1.0, CHCl3). IR
578
546
436
(film): 2935, 2865, 1710, 1450, 1370, 1300, 1135, 1080, 1035, 955, 855, 760, 700. 1H-NMR (400 MHz, CDCl3):
7.41 7.20 (m, 5 arom. C); 5.39 (dq, 3J(3',4') ˆ 10.2, 4J(2',3') ˆ 1.1, HÀC(3')); 4.64 (q, 3J(1'',2'') ˆ 6.2, HÀC(1''));
4.14 (d, 3J(1',2) ˆ 9.6, HÀC(1')); 4.07 (dq, 3J(3',4') ˆ 10.2, J(4',5') ˆ 6.7, HÀC(4')); 2.81 (s, MeSO2); 2.62 1.67
3
(m, HÀC(2), H2C(3), H2C(4), H2C(5), H2C(6)); 1.81 (d, 4J(2',3') ˆ 1.1, MeÀC(2')); 1.50 (d, 3J(4',5') ˆ 6.7,
Me(5')); 1.36 (d, 3J(1'',2'') ˆ 6.2, Me(2'')). 13C-NMR (100.6 MHz, CDCl3): 211.7 (s, C(1)); 143.9, 142.0 (2s,
arom. C, C(2')); 128.2 (d, 1J(C,H) ˆ 159, 2 arom. C); 126.8 (d, 1J(C,H) ˆ 160, 2 arom. C); 126.0 (d, 1J(C,H) ˆ
158, arom. C); 121.8 (d, 1J(C,H) ˆ 154, C(3')); 73.8, 72.2 (2d, 1J(C,H) ˆ 143, 148, C(1'), C(1'')); 58.6
(d, 1J(C,H) ˆ 140, C(4')); 54.4 (d, 1J(C,H) ˆ 123, C(2)); 43.0 (t, 1J(C,H) ˆ 131, C(6)); 37.6 (q, 1J(C,H) ˆ 138,
MeSO2); 32.2, 29.0, 24.9 (3t, 1J(C,H) ˆ 126, C(3), C(4), C(5)); 22.2 (q, 1J(C,H) ˆ 130, C(2'')); 19.6 (q, 1J(C,H) ˆ
.
130, MeÀC(2')); 15.6 (q, 1J(C,H) ˆ 126, C(5')). CI-MS (NH3): 374 (1, M ), 320 (11), 292 (47), 257 (32), 179
‡
(26), 122 (13), 105 (39). Anal. calc. for C21H56O4S (374.50): C 67.35, H 7.00, S 8.56; found: C 67.33, H 7.24, S 8.65.
3) Absolute configurations could not be established unambiguously. They are proposed to be analogous to those
given for (À)-13a and 14a.

1684
Helvetica Chimica Acta Vol. 85 (2002)
25
25
25
Data of (À)-14b: Colorless oil. [a]2D5 ˆ À17, [a] ˆ À18, [a] ˆ À21, [a] ˆ À32 (c ˆ 0.9, CHCl3). IR
578
546
436
(film): 2935, 2865, 1710, 1450, 1375, 1300, 1130, 1080, 1040, 955, 765, 700. 1H-NMR (400 MHz, CDCl3): 7.41 7.20
(m, 5 arom. C); 5.39 (dq, 3J(3',4') ˆ 10.2, 4J(2',3') ˆ 1.1, HÀC(3')); 4.64 (q, 3J(1'',2'') ˆ 6.2, HÀC(1'')); 4.14
(d, 3J(1',2) ˆ 9.6, HÀC(1')); 4.07 (dq, 3J(3',4') ˆ 10.2, 3J(4',5') ˆ 6.7, HÀC(4')); 2.81 (s, MeSO2); 2.62 1.67
(m, HÀC(2), H2C(3), H2C(4), H2C(6)); 1.81 (d, 4J(2',3') ˆ 1.1, MeÀC(2')); 1.50 (d, 3J(4',5') ˆ 6.7, Me(5')); 1.36
(d, 3J(1'',2'') ˆ 6.2, Me(2'')). 13C-NMR (100.6 MHz, CDCl3): 211.0 (s, C(1)); 143.2, 141.3 (2s, arom. C, C(2'));
128.2 (d, 1J(C,H) ˆ 162, 2 arom. C); 126.9 (d, 1J(C,H) ˆ 160, 2 arom. C); 123.2 (d, 1J(C,H) ˆ 156, arom. C);
121.8 (d, 1J(C,H) ˆ 154, C(3')); 74.7, 73.0 (2d, 1J(C,H) ˆ 141, 143, C(1'), C(1'')); 57.7 (d, 1J(C,H) ˆ 139, C(4'));
54.1 (d, 1J(C,H) ˆ 128, C(2)); 42.0 (t, 1J(C,H) ˆ 129, (C(6)); 37.8 (q, 1J(C,H) ˆ 138, MeSO2); 30.7, 28.6, 25.9
(3t, 1J(C,H) ˆ 127, 132, 132, C(3), C(4), C(5)); 22.3 (q, 1J(C,H) ˆ 130, C(2'')); 19.9 (q, 1J(C,H) ˆ 126,
.
‡
MeÀC(2')); 15.8 (q, 1J(C,H) ˆ 129, C(5')). CI-MS (NH3): 392 (1, [M ‡ 18] ), 374 (2, M ), 370 (39), 292
‡
(40), 275 (22), 257 (16), 194 (100), 142 (10), 97 (12), 79 (4).
(À)-(2S)- and (À)-(2R)-2-{(1S,2Z,4R)-2-Methyl-4-(methylsulfonyl)-1-[(S)-1-(pentafluorophenyl)ethoxy]-
pent-2-en-1-yl}cyclohexanone ((À)-13c and (À)-14c)3). As described for (À)-13a, with (À)-4c (42 mg,
0.14 mmol) and 12 (0.1 ml, 0.5 mmol). 1H-NMR spectrum of the crude product showed a 1.2 :1 mixture of
(À)-13c and (À)-14c. CC (SiO2, AcOEt/light petroleum ether 1:3, Rf ((À)-13c) ˆ 0.25, Rf ((À)-14c) ˆ 0.21)
afforded (À)-13c (4 mg, 6%) and (À)-14c (7 mg, 13%).
25
25
25
Data of (À)-13c: Colorless oil. [a]2D5 ˆ À79, [a] ˆ À80, [a] ˆ À92, [a] ˆ À172 (c ˆ 0.4, CHCl3). IR
578
546
436
(film): 2940, 2860, 1710, 1485, 1455, 1300, 1135, 1085, 1035, 940, 760. 1H-NMR (400 MHz, CDCl3): 5.41
(dq, 3J(3',4') ˆ 11.1, 4J(2',3') ˆ 1.2, HÀC(3')); 4.97 (q, 3J(1'',2'') ˆ 6.7, HÀC(1'')); 4.26 (dq, 3J(3',4') ˆ 11.1,
3J(4',5') ˆ 6.7, HÀC(4')); 4.12 (d, 3J(1',2) ˆ 8.3, HÀC(1')); 2.89 (s, MeSO2); 2.79 1.67 (m, HÀC(2), H2C(3),
H2C(4), H2C(5), H2C(6)); 1.87 (d, 4J(2',3') ˆ 1.2, MeÀC(2')); 1.54 (d, 3J(4',5') ˆ 6.7, Me(5')); 1.53 (d, 3J(1'',2'') ˆ
6.7, Me(2'')). 13C-NMR (100.6 MHz, CDCl3): 211.2 (s, C(1)); 144.8 (br. d, 1J(C,F) ˆ 330, 3 arom. C); 144.2
(br. d, 1J(C,F) ˆ 330, 2 arom. C); 142.7 (s, C(2')); 121.5 (d, 1J(C,H) ˆ 150, C(3')); 118.0 (s, arom. C); 74.9
(d, 1J(C,H) ˆ 141, C(1')); 67.4 (d, 1J(C,H) ˆ 148, C(1'')); 58.2 (d, 1J(C,H) ˆ 145, C(4')); 55.0 (d, 1J(C,H) ˆ 128,
C(2)); 42.6 (t, 1J(C,H) ˆ 124, C(6)); 37.6 (q, 1J(C,H) ˆ 139, MeSO2); 30.7, 28.4, 24.8 (3t, 1J(C,H) ˆ 129, C(3),
C(4), C(5)); 21.0, 20.9 (2q, 1J(C,H) ˆ 129, C(2''), MeÀC(2')); 15.1 (q, 1J(C,H) ˆ 129, C(5')). CI-MS (NH3): 486
.
‡
‡
(15, [M ‡ 18] ), 468 (1, M ), 399 (25), 348 (6), 275 (10), 246 (15), 212 (45), 124 (12), 97 (6).
25
25
25
Data of (À)-14c: Colorless oil. [a]2D5 ˆ À45, [a] ˆ À47, [a] ˆ À54, [a] ˆ À95 (c ˆ 0.7, CHCl3). IR
578
546
436
(film): 2940, 1710, 1640, 1485, 1455, 1300, 1130, 1085, 935. 1H-NMR (400 MHz, CDCl3): 5.57 (dq, 3J(3',4') ˆ 10.8,
4J(2',3') ˆ 1.4, HÀC(3')); 4.98 (q, 3J(1'',2'') ˆ 6.7, HÀC(1'')); 4.28 (dq, 3J(3',4') ˆ 10.8, J(4',5') ˆ 6.1, HÀC(4'));
3
4.12 (d, 3J(1',2) ˆ 8.3, HÀC(1')); 2.91 (s, MeSO2); 2.36 1.67 (m, HÀC(2), H2C(3), H2C(4), H2C(4), H2C(6));
1.83 (d, 4J(2',3') ˆ 1.4, MeÀC(2')); 1.52 (d, 3J(4',5') ˆ 6.1, Me(5')); 1.43 (d, 3J(1'',2'') ˆ 6.7, Me(2'')). 13C-NMR
(100.6 MHz, CDCl3): 209.9 (s, C(1)); 144.8 (br. d, 1J(C,F) ˆ 326, 3 arom. C); 143.5 (br. d, 1J(C,F) ˆ 327,
2 arom. C); 141.6 (s, C(2')); 122.7 (d, 1J(C,H) ˆ 164, C(3')); 117.7 (s, arom. C); 118.0 (s, arom. C); 75.4
(d, 1J(C,H) ˆ 146, C(1')); 67.4 (d, 1J(C,H) ˆ 140, C(1'')); 57.6 (d, 1J(C,H) ˆ 140, C(4')); 54.4 (d, 1J(C,H) ˆ 125,
C(2)); 42.6 (t, 1J(C,H) ˆ 128, C(6)); 37.9 (q, 1J(C,H) ˆ 140, MeSO2); 31.5, 29.0, 25.3 (3t, 1J(C,H) ˆ 128, C(3),
C(4), C(5)); 21.7, 21.0 (2q, 1J(C,H) ˆ 125, C(2''), MeÀC(2')); 15.6 (q, 1J(C,H) ˆ 129, C(5')). CI-MS (NH3): 486
.
‡
‡
‡
(33, [M ‡ 18] ), 469 (2, [M ‡ 1] , 468 (1, M ), 399 (22), 348 (19), 310 (14), 275 (18), 222 (26), 139 (22), 97 (5).
Crystal-Structure Determination of (Æ)-10, (Æ)-11, and (À)-13a. The colorless crystals were mounted on a
Bruker CCD system equipped with graphite-monochromated Mo radiation, and a hemisphere of intensities was
collected. The structures were solved by means of SIR97 [15], and refined by means of SHELXT [16]. All non-
H-atoms were refined anisotropically, but the H-atoms isotropically. Crystallographic data, see Tables 1
3
(excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge
Crystallographic Data Centre as supplementary publication No. CCDC-175446 ((Æ)-10), CCDC-175447 ((Æ)-
11), and CCDC-175448 ((À)-13a). Copies of the data can be obtained, free of charge, on application to CCDC,
12, Union Road, Cambridge CB2 1EZ, UK (fax: ‡44(1223)336033; e-mail: deposit@ccdc.cam.ac.uk).
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Received December 21, 2001