Cu(I)-catalyzed stereospecific coupling reactions of enantioenriched α-stannylated benzyl carbamates and their application

Article abstract of DOI:10.1016/j.tet.2008.06.092

Enantioenriched α-stannylated benzyl carbamates were used in highly stereospecific coupling reactions employing Cu(I) as catalyzing transition metal. Acid chlorides and allyl bromide derivatives were used as electrophilic coupling partners. The reaction w

Full text of DOI:10.1016/j.tet.2008.06.092

Tetrahedron 64 (2008) 9123–9135
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Cu(I)-catalyzed stereospecific coupling reactions of enantioenriched
a-stannylated benzyl carbamates and their application
*
Heiko Lange, Roland Fro¨hlich, Dieter Hoppe
Organisch-Chemisches Institut, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Corrensstraße 40, 48149 Mu¨nster, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 9 May 2008
Received in revised form 24 June 2008
Accepted 24 June 2008
Available online 28 June 2008
Enantioenriched a-stannylated benzyl carbamates were used in highly stereospecific coupling reactions
employing Cu(I) as catalyzing transition metal. Acid chlorides and allyl bromide derivatives were used as
electrophilic coupling partners. The reaction was applied in the synthesis of two highly enantioenriched
indanoles and one enantioenriched tetraline via intramolecular cyclization reactions.
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords:
C–C coupling
Benzylic stannanes
Intramolecular cyclization reactions
Indanoles
Tetralines
1. Introduction
and as we had noticed highly stereospecific coupling reactions
of allylic stannanes,14 we became interested in the use of the
Organostannanes are widely used in synthetic organic chemis-
try as valuable building blocks for the formation of carbon–carbon
bonds via coupling reactions.1 Besides the well established Stille
reaction, where palladium is used as catalyzing transition metal,2
copper-(co-)catalyzed Stille-type reactions emerged during the last
years.1,2 Although used as catalyst or promoter itself in numerous
applications,3 copper was found to be a versatile co-catalyst in
Stille-type reactions as firstly systematically demonstrated by Lie-
beskind and co-workers.4–7 Nowadays, various examples exist in
which copper is used as the only catalytic or promoting transition
metal;1,4c,7–11 thereby, a broad variety of substrates has been
employed, utilizing both sp2- and sp3-hybridized tin moieties
bearing carbon centers (Fig. 1). Very often, these carbons are ad-
ditionally attached to functional groups via different heteroatoms.
During their studies in this field of transition metal catalyzed
coupling reactions, Falck and co-workers also have reported on
stereospecific copper(I)-catalyzed coupling reactions of various
a-stannylated benzyl carbamates in stereospecific coupling re-
actions.15 Herein we report on both our results concerning cop-
per(I)-catalyzed coupling reactions of different benzyl-type
stannanes with allyl bromide derivatives and acid chlorides and the
application of the procedure in synthetic problems.
2. Catalyst screening and discussion of the stereochemistry
Choosing the coupling of a-stannylated benzyl carbamate 6 with
allyl bromide in toluene16 as the reaction for catalyst screening, we
obtained the results outlined in Table 1.17 Independent of the
Bu3Sn
O
Bu3Sn
O
Bu3Sn
*
*
*
alkyl
O
alkyl
O
Ph
alkyl
O
O
1
2
3
stannanes, among them a
-oxygenated benzylstannanes 4.12 How-
Bu3Sn
R
S
Bu3Sn
O
ever, no statements have been made concerning the stereospecific
copper(I)-catalyzed coupling reaction of highly enantioenriched,
*
*
O
N
R
O
NiPr2
O-protected
a reliable asymmetric method for synthesizing highly enantioen-
riched
-stannylated benzyl carbamates 6 and 7 in high yields,13
a-stannylated benzyl alcohols. As we have developed
OCb
R = C6H5
R = C10H7
a
4
5
R = alkyl
R = aryl
6
7
* Corresponding author. Tel.: þ49 251 83 33275; fax: þ49 251 83 36531.
E-mail address: dhoppe@uni-muenster.de (D. Hoppe).
Figure 1. Different organostannanes already used in copper-catalyzed coupling re-
actions (1–5) and -stannylated benzyl carbamates 6 and 7.
a
0040-4020/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2008.06.092

9124
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
Table 1
Results of catalyst screening
Bu3Sn
O
O
*
*
a)
O
NiPr2
O
NiPr2
6
8
20
Entry
Stannane 6 (R/S) (% ee)
Cu(I)X (mol %)
t (coupling) (h)
Yield (%)
[a
]
(c, CHCl3)
% ee
Configuration of product 8
Stereospecificity S (%)
D
1a
2b
3a
4c
5c
(R)-6 (80)
(S)-6 (93)
(R)-6 (80)
(S)-6 (99)
(S)-6 (99)
CuCN (10)
CuCN (10)
CuI (10)
CuCN$2LiCl (10)
CuTCd (10)
24
48
40
36
36
87
74
59
74
74
þ3.0 (1.07)
ꢀ3.3 (1.56)
d
75
90
76
95
96
R
S
R
S
S
94
97
95
96
97
d
ꢀ3.7 (1.02)
Reaction conditions: (a) cat. Cu(I)X, allyl bromide, toluene, 70 ꢁC, t (coupling).
a
Stannane (R)-6 was synthesized using (ꢀ)-sparteine as chiral ligand; see Ref. 13c for details.
b
Stannane (S)-6 was synthesized using bis(oxazoline) ligand 27 as described in Refs. 13a,b; epimeric complexes not fully equilibrated when being trapped with tributyltin
chloride.
c
Stannane (S)-6 was synthesized using bis(oxazoline) ligand 27 as described in Refs. 13a,b.
d
CuTC: copper(I) thiophene-2-carboxylate.17
Br
copper(I)-salt employed and the enantioenrichment of the stan-
nane used, all reactions took place with the same stereospecificity S
of about 95%. Since the counter ion seems to have no influence on
the stereochemistry, all the copper(I) sources can be used in fact.
The results further show that the intermediate copper species must
be configurationally stable. We assume that the carbamate group
plays an important role here, as it can coordinate to the copper by
its carbonyl oxygen atom.18 The best yield (87%) and the best ste-
reospecificity was obtained when the reaction was catalyzed by
CuCN under ‘sealed tube’ conditions (Table 1, entries 2 and 3).
10 mol % of copper(I) salt turned out to be the minimum catalyst
loading; lower loadings resulted in poorer conversion and yields.
The absolute configurations of both the substrate and the pro-
ductddetermined via comparison of their optical rotations with
literature values13dreveal that the reactions took place with net
retention of configuration (Scheme 1). The entire reaction can be
separated into one transmetallation step and one substitution step.
It is known that the tin–copper transmetallation proceeds under
retention of configuration;19 therefore the substitution step must
be retentive as well. These findings fit in the current knowledge
concerning this kind of reactions19a,g,20,21 and are underlined by
further experiments (vide infra).
O
SnBu3
a)
OCb
OCb
(+)-(S)-9
(+)-(R)-6
80% ee
37%
78% ee
Scheme 2. Coupling of stannane 6 with para-bromobenzoyl chloride. Reaction con-
ditions: (a) 10 mol % CuCN, 4-Br-C6H4C(]O)Cl, toluene, 70 ꢁC, 36 h.
outlined in Scheme 1 to scope the reaction. The results are listed in
Table 2. Employing trans-crotyl bromide as electrophilic coupling
partner resulted in an inseparable complex mixture of linear SN2
coupling by-product and branched SN20 coupling products 10 as di-
astereomeric mixture with a slight preference for the trans-isomer
(Table 2, entry 1).23 Formation of diastereomers here arises from
a non stereodifferentiating attack at the double bond. It was not
possible to determine the enantiomeric ratios of the products; the
overall yield was satisfying. Coupling of trans-bromo-crotonic acid
methyl ester24 yielded desired ester 12 as an inseparable syn/anti-
mixture in 64% overall yield (Table 2, entry 2). The enantiomeric ex-
cess was determined from the mixture of diastereomers to be greater
than 90% ee, corresponding to a stereospecificity S greater than 93%
for this coupling partner. Noteworthy, we did not find a linear cou-
pling product emerging from a SN2 type reaction in this case.
Bu3Sn
[Cu]
OCb
retention
retention
OCb
OCb
(R)-8
(R)-6
Scheme 1. Stereochemical aspects of the coupling reaction outlined in Table 1.
C14
C13
C15
C16
The amount of observed stereospecificity S as well as the net
retention of configuration for the complete reaction was confirmed
when para-bromobenzoyl chloride was used as electrophilic cou-
pling partner (Scheme 2). Starting from stannane (R)-6 (er¼90:10),
ketone (S)-9, formed in 37% yield, exhibited an enantiomeric ratio
of 89:11 in favor of the S-configured enantiomer as it could be
determined from both the comparison of optical rotation with the
literature values13 and an X-ray crystal structure analysis under
anomalous dispersion (Fig. 2).
C25
O17
C12
C11
O9
C26
C4
C2
C5
C24
N20
C10
C18
C8
C3
C6
C7
O19
Br1
C22
C21
3. Scope and limitations
C23
We then used different allyl bromides and acid chlorides as
electrophilic coupling partners under the reaction conditions
Figure 2. X-ray crystal structure of ketone (þ)-(S)-9.22

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9125
Table 2
Results of further coupling experiments employing benzylstannanes
Bu3Sn
Ar
O
R
O
10
12
13
9
Ar = phenyl
R' = CH(CH3)CH=CH2
*
*
a)
CH(CO2CH3)CH=CH2
O
NiPr2
Ar
O
NiPr2
R'' = C(=O)C6H5
C(=O)C6H4-Br
C(=O)tBu
Ar = phenyl
6
14
α-naphthyl
7
R' = CH2CH=CH2
R'' = C(=O)C6H4-Br
C(=O)tBu
15
Ar = α-naphthyl
16
17
20
Entry
1
Stannane
(R/S) (% ee)
Coupling partner
t (coupling) (h)
Yield (%)
66c
dr
[
a
]
(c, CHCl3)
% eea
n.d.d
Product/
configuration
Stereospecificity S (%)
D
syn-10/S,R;
anti-10/S,S
(S)-6 (97)b
16
1.4:1
1.1:1
d
d
n.d.
Br
O
syn/>90;e
anti/>90e
syn-12/S,R;
anti-12/S,S
syn/>93;
anti/>93
(S)-6 (97)b
48
64
Br
2
O
3
4
(R)-6 (31)f
(S)-6 (98)b
36
48
48
54
d
d
þ59.5 (0.89)
ꢀ183.6 (0.98)
30
92
13/S
13/R
95
94
O
Ph
Cl
O
5
6
(R)-6 (80)g
(S)-6 (98)b
36
48
37
50
d
d
þ79.5 (1.25)
ꢀ120.2 (1.01)
78
94
9/S
9/R
97
96
Br-C6H4
Cl
O
7
(R)-6 (80)g
(S)-6 (98)b
(S)-7 (99)h
(S)-7 (99)h
36
36
16
18
d
37
80
66
d
d
d
d
d
d
d
d
(NO2)2C6H3
O
Cl
8
ꢀ200.2 (0.66)
þ26.3 (0.96)
ꢀ277.8 (0.74)
93
14/R
15/S
16/R
95
96
98
tBu
Cl
9
95% op
97
Br
O
10
Br-C6H4
Cl
O
11
(S)-7 (99)h
36
44
d
þ58.6 (0.22)
n.d.
17/R
n.d.
tBu
Cl
Reaction conditions: (a) 10 mol % CuCN, coupling partner, toluene, 70 ꢁC, t (coupling).
a
Determined by HPLC on chiral stationary phase; see Section 6 for details.
Stannane (S)-6 was synthesized using bis(oxazoline) ligand 27; see Refs. 13a,b.
b
c
Product contains the linear SN2-reaction product ((E)-N,N-diisopropylcarbamic acid 1-phenyl-pent-3-enyl ester) as by-product.
Due to the linear side product, the determination of the enantiomeric excess was not possible.
Determined out of the mixture of diastereomers. The signal of the second enantiomers was not detectable.
Stannane (R)-6 was synthesized using (ꢀ)-sparteine; see Refs. 13a,b.
d
e
f
g
h
Stannane (R)-6 was synthesized using (ꢀ)-sparteine; see Ref. 13c.
Stannane (S)-7 was synthesized using bis(oxazoline) ligand; see Refs. 13a,b.
The experiments shown in entries 4–8 in Table 2 underline the
11). Couplings employing allyl bromide and different acid chlorides
result presented in Scheme 2 and discussed above. Unsubstituted
benzoyl chloride reacts in moderate yields up to 56% with the
expected stereospecificity. Extension of the reaction time improved
the yield of 9 in the coupling of para-bromobenzoyl chloride up to
50% (Table 2, entry 6; for entry 5, compare Scheme 2) without
change in stereospecificity. 2,4-Dinitrobenzoyl chloridedidnotreact
under these conditions (Table 2, entry 7), thereby revealing that
electron-poor coupling partners are problematic. Aliphatic pivaloyl
chloride can be used as well (Table 2, entry 8). Albeit formed in
comparably moderate 37% yield, the enantioenrichment of aliphatic
ketone 14 (93% ee) shows 95% retention of configuration.
proceeded in good yields with very high stereospecificity S.
4. Intramolecular cyclization reactions
We then used the reaction presented above in intramolecular
cyclization reactions in order to gain access to indanoles and similar
structures.25 The cyclization precursor 25 was synthesized
straightforward as it is displayed in Scheme 3.
ortho-Iodo-benzyl carbamate 18 was transformed into stannane
19 according to protocols developed by Knochel and co-workers.26
Stannane 19 was then coupled to trans-bromo-crotonic acid methyl
ester under standard Stille-type conditions to form the carbon
skeleton of the cyclization precursor (E)-20. Further standard
Employing highly enantioenriched
a-stannylated 1-naphth-1-
ylmethyl carbamate 7 delivered similar results (Table 2, entries 9–

9126
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
OCb
OCb
OCb
OCb
OCb
OCb
O
O
O
O
b)
a)
a)
b)
R
R
O
O
I
SnBu3
I
SnBu3
R = COOCH3
R = COOCH3
18
19
(E)-20
28
29
(E)-30
79%
44%
E/Z > 98:2, 86%
E/Z > 98:2, 98%
c)
d)
Et Et
c)
d)
R =CH2OH ((E)-21)
E/Z > 98:2, 84%
R =CH2OTBS ((E)-22)
E/Z > 98:2, 67%
R =CH2OH ((E)-31)
E/Z > 98:2, 81%
Et Et
O
O
O
O
N
N
R =CH2OTES ((E)-32)
E/Z > 98:2, 80%
N
N
tBu
tBu
27
But
tBu
Sn(Bu)3
27
Sn(Bu)3
e)
e)
OCb
O
O
OCb
f)
f)
X
X = OH ((−)-(S)-(E)-34)
E/Z > 98:2, 97% ee, 61%
X = OH ((+)-(S)-(E)-24)
E/Z > 98:2, 97% ee, 81%
X
(−)-(S)-(E)-23 X = OTBS
E/Z > 98:2, 97% ee, 95%
(−)-(S)-(E)-33 X = OTES
E/Z > 98:2, 97% ee, 71%
g)
g)
X = Br ((−)-(S)-(E)-35)
E/Z > 98:2, 97% ee, 75%
X = Br ((−)-(S)-(E)-25)
E/Z > 98:2, 97% ee, 74%
OCb
OCb
OCb
OCb
h)
O
O
O
+
h)
+
O
(−)-(1S,2S)-26
(−)-(1S,2R)-26
(1S,2S)-36 d.r. = 1.1 : 1
95% ee
(1S,2R)-36
92% ee
42%
42%
60%
98% ee
70% ee
Scheme 4. Synthesis of indanoles 36. Reaction conditions: (a) (i) nBuMgCl, nBuLi, THF,
ꢀ78 ꢁC, 2 h; (ii) Bu3SnCl, THF, ꢀ78 ꢁC/rt, 4 h; (b) 10 mol % Pd2(dba)3, (E)-4-bromo-
crotonic acid methyl ester, DMF, 70 ꢁC, 36 h; (c) DIBAL-H, THF, ꢀ78 ꢁC, 1 h; (d) NEt3,
Scheme 3. Synthesis of indanoles 26. Reaction conditions: (a) (i) iPrMgCl, THF, ꢀ40 ꢁC;
2 h; (ii) Bu3SnCl, THF, ꢀ40 ꢁC/rt, 4 h; (b) 10 mol % Pd2(dba)3, (E)-4-bromo-crotonic
acid methyl ester, DMF, 60 ꢁC, 60 h; (c) DIBAL-H, THF, ꢀ78 ꢁC, 1 h; (d) NEt3, cat. DMAP,
s
s
cat. DMAP, TESCl, THF, rt, 12 h; (e) (i) bis(oxazoline) 27, BuLi, Et2O, ꢀ78 ꢁC, 2.5 h; (ii)
TBSCl, THF, rt, 12 h; (e) (i) bis(oxazoline) 27, BuLi, Et2O, ꢀ78 ꢁC, 2.5 h; (ii) Bu3SnCl,
Bu3SnCl, ꢀ78 ꢁC, 3 h; (iii) MeOH, H2O; (f) TFA, THF/H2O¼1:1, 0 ꢁC, TLC control; (g)
ꢀ78 ꢁC, 3 h; (iii) MeOH, H2O; (f) TBAF, THF/Et2O¼3:2, 0 ꢁC, 12 h (TLC control); (g) PPh3,
PPh3, CBr4, CH2Cl2, rt, 1 h; (h) CuCN (15 mol %), toluene, 70 ꢁC, 72 h.
CBr4, CH2Cl2, rt, 1 h; (h) CuCN (20 mol %), toluene, 70 ꢁC, 72 h.
standard transformations33 including an asymmetric stannylation
in order to form the benzylic stereogenic center. Again, the copper
catalyzed coupling reaction proceeded stereospecifically (S¼95–
98%), resulting in an inseparable 1:1-mixture (60% yield) of highly
enantioenriched indanole derivatives trans-36 (95% ee) and cis-36
(92% ee).34 Here again, the formation of the cis-isomer suffers from
a somewhat lower stereospecificity.
Tetraline systems can be obtained via this procedure as well as it
is outlined in Scheme 5. The synthesis of the enantioenriched cy-
clization precursor (ꢀ)-(S)-(E)-41 started with a B-alkyl Suzuki–
transformations delivered primary benzyl carbamate (E)-22.
Asymmetric stannylation employing bisoxazoline (ꢀ)-(S,S)-2727 for
induction of chiral information yielded a-stannylated benzyl car-
bamate (ꢀ)-(S)-(E)-23 in 95% yield. Desilylation afforded allyl al-
cohol (ꢀ)-(S)-(E)-24.28 On this stage, the enantiomeric excess was
determined to be 97% ee. An Appel reaction finally afforded cycli-
zation precursor (ꢀ)-(S)-(E)-25.29 The double bond geometry
remained untouched during the transformations.
Intramolecular coupling of stannane 25 was achieved employ-
ing 15 mol % CuCN (Scheme 3), and the desired O-carbamoylated
indanole was obtained as a 1:1-mixture of the trans- and the cis-
product, which could be separated by simple flash chromatogra-
phy.30 Whereas trans-26 was formed with high stereospecificity
(98% ee), the cis-isomer cis-26 was only formed with 72% retention
of configuration here. The reasons remain unknown so far.
Concerning mechanistical aspects we assume that the initial
tin–copper transmetallation is followed by a complexation of the
intermediate copper species by the olefin. Within this complex the
C–C bond formation takes place, finally forming vinylic double
bond in indanoles 26.
9-BBN
OCb
OCb
OTES
(E)-(37)
OTES
a)
I
(E)-38
17
E/Z > 98:2, 83%
Sn(Bu)3
OCb
Sn(Bu)3
b)
c)
OCb
X
OTES
The absolute configuration of the cyclization products was ra-
tionalized as follows. We have shown earlier that the bis(oxazoline)
27 containingepimeric lithium complexes formed of primary benzyl
carbamates equilibrate and that the (RC)-configured epimer is
strongly favored under the reactions conditions, which were
employed here as well.13 We have further shown that these facts are
not influenced by ortho-substituents on the aryl moiety.13c Trapping
of the equilibrated lithium species with tributyltin chloride pro-
ceeds under inversion of configuration, delivering (S)-configured
stannanes. Stereospecific coupling as outlined above therefore
yields the (1S)-configured cyclic products trans- and cis-26 here.
Comparable results were obtained when cyclization of
precursor (ꢀ)-(S)-(E)-35 was performed by using this coupling
procedure (Scheme 4). Highly enantioenriched precursor (ꢀ)-(S)-
(E)-35 was derived from carbamoylated benzyl alcohol 2831,32 by
(−)-(S)-(E)-40 X = OH
E/Z > 98:2, 72% ee, 65%
(−)-(S)-(E)39
E/Z > 98:2, 72% ee, 66%
d)
e)
(−)-(S)-(E)-41 X = Br
E/Z > 98:2, 72% ee, 97%
OCb
OCb
+
(1S,2R)-42
68% ee
(1S,2S)-42 d.r. = 1.5:1
66%
70% ee
Scheme 5. Synthesis of tetralines 42. Reaction conditions: (a) (i) 9-BBN, (E)-37; (ii)
K3PO4, 3 mol % Pd(PPh3)4, DMF, 60 ꢁC, 32 h; (b) (i) bis(oxazoline) ligand 27, sBuLi, Et2O,
ꢀ78 ꢁC, 2.5 h; (ii) Bu3SnCl, ꢀ78 ꢁC, 3 h; (iii) MeOH, H2O; (c) TFA, THF/H2O¼1:1, 0 ꢁC,
TLC control; (d) PPh3, CBr4, CH2Cl2, rt, 1 h; (e) CuCN (15 mol %), toluene, 70 ꢁC, 72 h.

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9127
Miyaura coupling reaction35 in order to attach the unsaturated side
chain to benzyl carbamate 17. This reaction was followed by an
asymmetric stannylation according to the standard protocol13
yielding stannane 39 in moderate yield (66%) and with comparably
low enantioselectivity of 72% ee, which again was measured at the
stage of allyl alcohol derivative (ꢀ)-(S)-(E)-40. The more flexible
side chain is blamed to disturb the asymmetric stannylation here.
After formation of allyl bromide 41, the stereospecific coupling
procedure (94–97% retention of configuration) yielded dia-
stereomeric tetralines trans-42 (70% ee) und cis-42 (68% ee)34 in
66% yield as an inseparable mixture with the anti-isomer slightly
preferred (trans/cis¼1.5:1).
Multisolvent Delivery System and 996 PDA detector. Crystallo-
graphic data: data set was collected with a Nonius KappaCCD dif-
fractometer. Programs used: data collection COLLECT (Nonius B.V.,
1998), data reduction Denzo-SMN,37 absorption correction
Denzo,38 structure solution SHELXS-97,39,40 structure refinement
SHELXL-97,41 graphics SCHAKAL.42 N,N-Dimethylamino pyridine
(DMAP), palladium tetrakis(triphenylphosphine) (Pd(PPh3)4), and
palladium dibenzylidene-acetone (Pd2(dba)3) were used as pur-
chased. Electrophilic coupling partners were purified before use
(exception: solids). Literature known compounds are not fully
characterized again. Bis(oxazoline) ligand 27 was prepared
according to the literature.27 Stannanes 6 and 7 were prepared as
described earlier.13 Spectroscopic data of coupling products 8, 9, 14,
and 15 correspond to the literature.13
5. Conclusion
We have shown that enantioenriched
a
-stannylated benzyl
6.2. Typical procedure for the synthesis of coupling products
8–10, 12–17 (GPA)
carbamates can be coupled with allyl bromides and acid chlorides
using CuCN as catalyst. The coupling reactions proceed with high
stereospecificity. The procedure was applied in the syntheses of
enantioenriched indanoles and an enantioenriched tetraline.
CuCN (dried) of 10 mol % was filled in a flame-dried Schlenk
tube, which is evacuated and flooded again with argon. Dry toluene
of 5.0 mL was then added. Electrophilic coupling partner
(0.36 mmol, 1.2 equiv) and 0.30 mmol (1.0 equiv) of benzyl stan-
nane were injected into this suspension. The reaction mixture was
stirred at 70 ꢁC for the given time (see Tables 1 and 2) under sealed
tube conditions until complete conversion of the stannane (TLC).
The reaction mixture is cooled down to rt and diluted with 10 mL of
TBME. Satd ammonia of 2 mL was added and the phases were
separated. The aqueous phase was extracted with TBME (3ꢂ10 mL),
and the combined organic layers were washed with brine, dried
over MgSO4, and concentrated in vacuo. The crude products were
purified by flash chromatography on silica gel with E/P-mixtures.
6. Experimental
6.1. General
All solvents were dried and purified prior to use. Toluene was
distilled over sodium/benzophenone. TESCl was distilled from
powdered CaH2 and stored under argon. sec-Butyllithium as solu-
tion in hexane/cyclohexane¼92:8 was filtered through Celite be-
fore use and its concentration was determined by titration against
diphenylacetic acid.36 E refers to: Et2O, H: n-hexane, P: pentane,
TBME: tert-butyl methyl ether, DMF: dimethylformamide. All air
and moisture sensitive reactions were performed under argon at-
mosphere in flame-dried glassware using septum and syringe
techniques. Flash column chromatography (FCC) was performed on
Merck 60 silica gel, 0.040–0.063 mm, using an argon pressure of
1.2–1.4 bar, and monitored by thin-layer chromatography (TLC) on
Merck 60 F254 silica gel. Gas chromatography was performed on
Agilent 6890 plus, Agilent, Bo¨blingen. HP 5, HP 1701 were used as
6.2.1. (ꢀ)-(S)-N,N-Diisopropylcarbamic acid (1-phenyl-but-3-enyl)
ester (8)
According to GPA, stannane 6 (93% ee, 158 mg, 0.30 mmol) was
reacted with allyl bromide (44 mg, 0.36 mmol) in the presence of
CuCN (2.7 mg, 0.03 mmol) to afford 8 (72 mg, 87%) as colorless oil.
20
Rf 0.65 (E/P¼1:1); tR 14.4 min (HP 5); [
HPLC: CHIRA-GROM
0.3 mL minꢀ1
a
]
D
ꢀ3.3 (c 1.56, CHCl3);
2
(2ꢂ250 mm),
H/iPrOH¼1000:1,
achiral columns (HP 5: 30 m long, 0.32
m
m diameter, 0.25 mm thick
,
l
210 nm, tR(ꢀ) 9.1 min, tR(þ) 11.5 min, 90% ee.
stationary phase, N2 as the mobile phase, 106 kPa pressure, 290 ꢁC
injection temperature, 300 ꢁC detꢀec1tor temperature, program:
6.2.2. (þ)-(S)-N,N-Diisopropylcarbamic acid [2-(4-bromo-phenyl)-
2-oxo-1-phenyl-ethyl] ester (9)
50 ꢁC start temperature, 10 ꢁC min
heating rate, 300 ꢁC final
temperature for 15 min) (HP 1701: 25 m long, 0.20
mm diameter,
According to GPA, stannane 6 (80% ee, 158 mg, 0.30 mmol) was
reacted with 4-bromobenzoyl chloride (79 mg, 0.36 mmol) in the
0.20 mm thick stationary phase, N2 as the mobile phase, 100 kPa
pressure, 250 ꢁC injection temperature, 300 ꢁC detector tempera-
ture, program: 50 ꢁC start temperature, 10 ꢁC minꢀ1 heating rate,
270 ꢁC final temperature for 20 min). Melting points were mea-
sured on an SMP3 melting point apparatus purchased from Stuart
Scientific, UK (uncorrected values). The optical rotations were
measured in a 10 cm cuvette on a polarimeter 341 purchased from
Perkin–Elmer. Unless otherwise stated, 1H and 13C NMR data were
recorded on Bruker ARX 300 and AMX 400; spectra were obtained
from solutions in CDCl3 (dC¼77.0 ppm) and were calibrated relative
to residual content of CHCl3 (dH¼7.24 ppm) or SiMe4 (dH¼0.0 ppm).
Peak multiplicities in 1H NMR spectra are abbreviated as s (singlet),
d (doublet), t (triplet), q (quartet), sept (septet), m (multiplet), br
(broad), and ps (pseudo). Diastereotopic methylene protons with
different chemical shifts are abbreviated as HA and HB. IR: Nicolet
5DCX, Bruker IFS 28 or Varian 3100 Excalibur Series with Specac
Golden Gate Single Reflection ATR. Elemental analyses were per-
formed at the Microanalytical Section of the Organisch-Chemisches
Institut, WWU Mu¨nster, on a Vario El III, purchased from Elementar
Analysen Systeme, Hanau (Germany). Mass spectrometric data
were obtained on Finnigan MAT 8230 (EI), Micromass Quattro LCZ
(ESI), Micromass MAT 8200 (GC-TOF/HRMS). HPLC: Waters 600E
presence of CuCN (2.7 mg, 0.03 mmol) to afford 9 (46 mg, 37%) as
20
colorless solid. Rf 0.34 (E/P¼1:2); tR 21.4 min (HP 5); [
a
]
þ79.5 (c
D
1.25, CHCl3); HPLC: CHIRA-GROM 2 (2ꢂ250 mm), H/iPrOH¼1000:1,
0.3 mL minꢀ1
,
l
210 nm, tR(ꢀ) 58.0 min, tR(þ) 79.1 min, 78% ee.
6.2.3. N,N-Diisopropylcarbamic acid (2-methyl-1-phenyl-but-3-
enyl) ester (10)
According to GPA, stannane 6 (97% ee, 158 mg, 0.30 mmol) was
reacted with trans-crotyl bromide (49 mg, 0.36 mmol) in the
presence of CuCN (2.7 mg, 0.03 mmol) to afford 10 as an in-
separable 1.4:1-mixture of diastereomers (GC), additionally con-
taining traces of linear coupling product, as colorless liquid (57 mg).
Data for syn-8 and anti-8: Rf 0.67 (E/P¼1:1); tR 11.6 min (1R,2S
*
),
12.2 min (1R,2R d 0.85 (d,
*
) (HP 5); 1H NMR (300 MHz, CDCl3)
3J¼6.9 Hz, 3H, –CH3 (1R,2S
*
)), 0.97 (d, 3J¼6.9 Hz, 3H, –CH3 (1R,2R
*
)),
1.14 (ps-s, 24H, (H3C)2CH– (1R,2S) and (1R,2R)), 2.48 (m, 1H, CHCH3
(1R,2S
*
)), 2.63 (m, 1H, CHCH3 (1R,2R )), 3.88 (ps-s, 4H, (H3C)2CH–
*
(1R,2S) and (1R,2R)), 4.93 (m, 4H, H2CCH– (1R,2S) and (1R,2R)), 5.60
(m, 4H, Hbenzylic, H2CCH– (1R,2S) and (1R,2R)), 7.13–7.32 (m, 10H, H-
ph, (1R,2S) and (1R,2R)); 13C NMR (75 MHz, CDCl3)
d
15.4 (CH3
(1R,2S
*
)), 16.5 (CH3 (1R,2R
*
)), 21.1 ((H3C)2CH– (1R,2S) and (1R,2R)),

9128
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
40.2 (H2CCH– (1R,2S
*
)), 43.2 (H2CCH– (1R,2R
)), 79.8 (Cbenzylic (1R,2R
115.3 (H2CCH– (1R,2S) and (1R,2R)), 125.2, 126.4, 127.1, 127.3, 127.9,
128.0 (C-ph without C-2 (1R,2S) and (1R,2R)), 139.7 (Cipso (1R,2S )),
140.2 (Cipso (1R,2R )), 154.8 (NC]O (1R,2S )), 155.0 (NC]O
(1R,2R
*
)), 45.8 ((H3C)2CH–
of CuCN (2.7 mg, 0.03 mmol) to afford 14 (35 mg, 37%) as colorless
20
(1R,2S) and (1R,2R)), 79.6 (Cbenzylic (1R,2S
*
*
)),
liquid. Rf 0.37 (E/P¼1:3); tR 14.5 min (HP 5); [
a
]
ꢀ200.2 (c 0.66,
D
CHCl3); HPLC: CHIRA-GROM 2 (2ꢂ250 mm), H/iPrOH¼1000:1,
*
0.2 mL minꢀ1
,
l
210 nm, tR(þ) 11.6 min, tR(ꢀ) 12.8 min, 93% ee.
*
*
*
)); IR (ATR) 3065, 3033, 2970, 2935, 2876, 1695, 1653, 1541,
6.2.7. (þ)-(S)-N,N-Diisopropylcarbamic acid 1-(naphth-1-yl-but-
3-enyl) ester (15)
According to GPA, stannane 7 (99% ee, 172 mg, 0.30 mmol) was
reacted with allyl bromide (44 mg, 0.36 mmol) in the presence of
1475, 1457, 1436 cmꢀ1; MS (ESI) m/z 312.1934 [MþNa]þ. Anal. Calcd
for C18H27NO2: C, 74.70; H, 9.40; N, 4.84. Found: C, 74.35; H, 9.47; N,
4.74.
CuCN (2.7 mg, 0.03 mmol) to afford 15 (78 mg, 80%) as colorless
20
6.2.4. 2-(N,N-Diisopropylcarbamoyloxy-2-phenyl-methyl)-but-3-
enoic acid methyl ester (12)
oil. Rf 0.64 (E/P¼1:1); tR 17.5 min (HP 5); [
a
]
þ26.3 (c 0.96, CHCl3),
D
95% op.
According to GPA, stannane 6 (97% ee, 158 mg, 0.30 mmol) was
reacted with trans-4-bromo-crotonic acid methyl ester (158 mg,
0.36 mmol) in the presence of CuCN (2.7 mg, 0.03 mmol) to afford
12 as an inseparable 1.1:1-mixture of diastereomers (GC) as color-
6.2.8. (ꢀ)-(R)-N,N-Diisopropylcarbamic acid [2-(4-bromo-phenyl)-
1-(naphth-1-yl)-2-oxo-ethyl] ester (16)
According to GPA, stannane 7 (99% ee, 172 mg, 0.30 mmol) was
reacted with 4-bromo-benzoyl chloride (79 mg, 0.36 mmol) in the
presence of CuCN (2.7 mg, 0.03 mmol) to afford 16 (106 mg, 75%) as
less liquid (52 mg, 52%). Data for syn-12 and anti-12: Rf 0.49
20
(E/P¼1:1); tR 13.5 min (1R,2R) and (1R,2S) (HP 5); [
a
]
ꢀ5.6 (c 0.75,
D
CHCl3); HPLC: CHIRA-GROM 2 (2ꢂ250 mm), H/iPrOH¼1000:1,
colorless highly viscous oil. Rf 0.69 (E/P¼1:1); tR 21.2 min (HP 5);
20
0.3 mL minꢀ1
,
l
210 nm, tR
(1S,2R
(300 MHz, CDCl3)
*
(1S,2S
*
) 15.4 min, tR(1R,2S
*
) 16.9 min,
[a
]
ꢀ277.1 (c 1.01, CHCl3); HPLC: CHIRA-GROM 2 (2ꢂ250 mm),
D
>90% ee; tR
*
*
) 18.3 min, tR(1R,2R
*
) 22.3 min, >90% ee; 1H NMR
H/iPrOH¼1000:1, 0.3 mL minꢀ1
,
l
¼210 nm, tR(þ) 29.3 min, tR(ꢀ)
d
1.52 (ps-s, 24H, (H3C)2CH– (1R,2S) and (1R,2R)),
35.1 min, 97% ee; 1H NMR (300 MHz, CDCl3)
d
1.08 (br d, 3J¼7.0 Hz,
3.50 (dd, 3J¼7.6, 9.3 Hz, 1H, –CH– (1R,2S)), 3.51 (s, 3H, –OCH3
(1R,2R)), 3.58 (dd, 3J¼3J¼9.4 Hz, 1H, –CH– (1R,2R)), 3.66 (s, 3H,
–OCH3 (1R,2S)), 3.87 (ps-s, 4H, (H3C)2CH– (1R,2R) and (1R,2S)),
4.90–5.20 (m, 4H, H2C]CH– (1R,2R) and (1R,2S)), 5.58 (ddd,
3J¼17.2, 8.9, 9.4 Hz, 1H, H2C]CH– (1R,2R)), 5.92 (d, 3J¼9.4 Hz, 1H,
Hbenzylic (1R,2R)), 5.93 (ddd, 3J¼17.2, 9.3, 9.3 Hz, 1H, H2C]CH–
(1R,2S)), 6.09 (d, 3J¼9.3 Hz, 1H, Hbenzylic (1R,2S)), 7.08–7.35 (m, 10H,
6H, (H3C)2CH–), 1.89 (d, 3J¼6.9 Hz, 6H, (H3C)2CH–), 3.76 (ps-s, 1H,
(H3C)2CH–), 3.98 (ps-s, 1H, (H3C)2CH–), 7.03–7.59 (m, 8H, Hbenzylic
,
H-2, H-3, H-7, H-ph), 7.67 (d, 3J¼8.6 Hz, 1H, H-6), 7.80 (br dd,
3J¼3J¼8.8 Hz, 2H, H-4, H-5,), 8.23 (d, 3J¼8.4 Hz, 1H, H-9); 13C NMR
(75 MHz, CDCl3)
d 21.2 ((H3C)2CH–), 46.4 ((H3C)2CH–), 74.9
(Cbenzlic), 123.5, 125.3, 125.4, 126.2, 127.1, 128.2, 128.3, 128.9, 129.0,
130.0, 130.1, 130.3, 131.4, 131.8, 133.8, 134.2, 137.9 (C-naph, C-ph),
154.5 (NC]O), 194.9 (C]O); IR (KBr) 3086, 3062, 3052, 2970, 2933,
2875, 1682, 1586, 1568, 1512, 1476, 1435 cmꢀ1; MS (ESI) m/z
468.1165 [MþH]þ. Anal. Calcd for C25H26BrNO3: C, 64.11; H, 5.60; N,
2.99. Found: C, 64.38; H, 5.50; N, 2.95.
H-ph (1R,2R) and (1R,2S)); 13C NMR (75 MHz, CDCl3)
d
20.9
((H3C)2CH– (1R,2R) and (1R,2S)), 45.9 ((H3C)2CH– (1R,2R) and
(1R,2S)), 51.8 (–CH– (1R,2R )), 51.9 (–CH– (1R,2S )), 56.7 (–OCH3
(1R,2R )), 57.5 (–OCH3 (1R,2S )), 76.0 (Cbenzylic (1R,2R )), 76.7
(Cbenzylic (1R,2S )), 119.9 (H2C]CH– (1R,2S )), 120.1 (H2C]CH–
(1R,2R )), 126.9, 127.4, 127.9, 128.0, 128.2, 128.2 (C-ph without Cipso
(1R,2S) and (1R,2R)), 131.3 (H2C]CH– (1R,2R )), 132.5 (H2C]CH–
(1R,2S )), 138.4 (Cipso (1R,2S )), 138.8 (Cipso (1R,2R )), 154.0 (NC]O
(1R,2R )), 154.2 (NC]O (1R,2S )), 171.1 (C]O (1R,2R )), 171.7 (C]O
(1R,2S
*
*
*
*
*
*
*
*
6.2.9. (þ)-(R)-N,N-Diisopropylcarbamic acid (3,3-di-methyl-1-
(naphth-1-yl)-2-oxo-butyl) ester (17)
According to GPA, stannane 7 (99% ee, 172 mg, 0.30 mmol) was
reacted with pivaloyl chloride (43 mg, 0.36 mmol) in the presence
*
*
*
*
*
*
*
*
)); IR (ATR) 3061, 3026, 2969, 2878, 1720, 1693, 1650, 1585,
of CuCN (2.7 mg, 0.03 mmol) to afford 17 (81 mg, 44%) as colorless
20
1549,1495, 1433 cmꢀ1; MS (ESI) m/z 356.1834 [MþNa]þ. Anal. Calcd
for C19H27NO4: C, 68.44; H, 8.16; N, 4.20. Found: C, 68.18; H, 8.28; N,
4.18.
solid. Rf 0.62 (E/P¼1:1); tR 20.4 min (HP 5); mp 103 ꢁC (E); [
a]
D
þ58.6 (c 0.22, CHCl3); 1H NMR (300 MHz, CDCl3)
d 1.00 (br s, 3H,
(H3C)(H3C)CH–), 1.06 (s, 9H, H3C–), 1.13 (br s, 3H, (H3C)(H3C)CH–),
1.24 (br d, 3J¼6.5 Hz, 6H, (H3C)2CH–), 3.69 (ps-s, 1H, (H3C)2CH–),
4.11 (ps-s, 1H, (H3C)2CH–), 7.13 (s, 1H, Hbenzylic), 7.41–7.63 (m, 4H, H-
2, H-3, H-6, H-7), 7.88–7.94 (m, 2H, H-4, H-5), 8.26 (dd, 3J¼8.4 Hz,
6.2.5. (þ)-(S)-N,N-Diisopropylcarbamic acid 2-oxo-1,2-diphenyl-
ethyl ester (13)
According to GPA, stannane 6 (31% ee, 158 mg, 0.30 mmol) was
reacted with benzoyl chloride (51 mg, 0.36 mmol) in the presence
4J¼0.9 Hz, 1H, H-7); 13C NMR (75 MHz, CDCl3)
d 20.6 ((H3C)2CH–),
27.0 ((H3C)3C–), 43.7 ((H3C)3C–), 45.9 ((H3C)2CH–), 73.7 (Cbenzylic),
123.6, 125.1, 126.0, 126.9, 128.1, 128.8, 129.9, 130.3, 131.6, 134.2 (C-
naph), 154.7 (NC]O), 211.2 (C-12); IR (KBr) 3055, 2970, 2934, 2872,
1716, 1687, 1598, 1512, 1477, 1437, 1368 cmꢀ1; MS (ESI) m/z
370.2405 [MþH]þ. Anal. Calcd for C23H31NO3: C, 74.76; H, 8.46; N,
3.79. Found: C, 75.03; H, 8.55; N, 3.82.
of CuCN (2.7 mg, 0.03 mmol) to afford 13 (49 mg, 48%) as colorless
20
solid. Rf 0.53 (E/P¼1:1); tR 18.7 min (HP 5); mp 129 ꢁC (E); [
a]
D
þ59.5 (c 0.89, CHCl3); HPLC: CHIRA-GROM
1
(2ꢂ250 mm),
H/iPrOH¼1000:1, 0.3 mL minꢀ1
,
l
210 nm, tR(ꢀ) 53.9 min, tR(þ)
68.2 min, 30% ee; 1H NMR (400 MHz, CDCl3)
d
1.20 (d, 3J¼6.8 Hz,
12H, (H3C)2CH–), 3.87 (ps-s, 1H, (H3C)2CHB), 4.04 (ps-s, 1H,
(H3C)2CHA–), 6.88 (s, 1H, Hbenzylic), 7.26–7.42 (m, 5H, Hortho, Hmeta
,
6.3. Synthesis of indanoles 26
Hpara0), 7.95 (dd, 3J¼8.7 Hz,
0
H
para), 7.44–7.53 (m, 3H, Hmeta
,
4J¼1.6 Hz, 2H, Hortho0); 13C NMR (100 MHz, CDCl3)
d
20.6 ((H3C)2CH–
6.3.1. N,N-Diisopropylcarbamic acid (2-iodo-benzyl) ester (18)
According to the procedure for carbamoylation of primary
benzyl carbamates described in Ref. 13, 2-iodo-benzyl alcohol
(1.45 g, 6.00 mmol) was dissolved in 10.0 mL of dry THF and
deprotonated using sodium hydride (263 mg, 6.90 mmol, suspen-
sion in mineral oil (60%)). N,N-Diisopropylcarbamic acid chloride
(1.13 g, 6.90 mmol) was added. Work-up according to Ref. 13 and
purification of the crude product by flash chromatography (E/
P¼1:4) yielded 1.70 g (78%) of benzyl carbamate 18 as slightly
yellow solid. Rf 0.56 (E/P¼1:1); tR 15.7 min (HP 5); mp 55 ꢁC (E); 1H
), 46.2 ((H3C)2CH–), 77.4 (Cbenzylic), 128.5, 128.6, 128.7, 128.8, 128.9,
133.1, 134.4, 135.1 (C-ph), 154.7 (NC]O), 195.2 (C]O); IR (KBr):
3065, 3007, 2974, 2931, 2872, 1677, 1596, 1475, 1446, 1440, 1384,
1368 cmꢀ1; MS (ESI) m/z 362.1737 [MþNa]þ. Anal. Calcd for
C
21H25NO3: C, 74.31; H, 7.42; N, 4.13. Found: C, 74.10; H, 7.40; N, 3.98.
6.2.6. (ꢀ)-(R)-N,N-Diisopropylcarbamic acid (3,3-di-methyl-2-
oxo-1-phenyl-butyl) ester (14)
According to GPA, stannane 6 (98% ee, 158 mg, 0.30 mmol) was
reacted with pivaloyl chloride (43 mg, 0.36 mmol) in the presence
NMR (300 MHz, CDCl3)
d
1.23 (d, 3J¼6.9 Hz, 12H, (H3C)2CH–), 3.95

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9129
(ps-s, 2H, (H3C)2CH–), 5.14 (s, 2H, Hbenzylic), 6.99 (ddd, 3J¼7.9, 7.6 Hz,
4J¼1.9 Hz, 1H, H-4), 7.33 (ddd, 3J¼7.9, 7.1 Hz, 4J¼1.1 Hz, 1H, H-5),
7.37 (dd, 3J¼7.1 Hz, 4J¼1.9 Hz, 1H, H-6), 7.84 (dd, 3J¼7.6 Hz,
(C-2), 147.2 (–CH2CH]CH–), 155.1 (NC]O), 166.8 (C]O); IR (ATR)
3067, 3032, 2966, 2927, 2871, 2852,1683,1671,1601,1559,1474,1446,
1436, 1376 cmꢀ1; MS (ESI) m/z 356.1833 [MþNa]þ. Anal. Calcd for
4J¼1.1 Hz, 1H, H-3); 13C NMR (75 MHz, CDCl3)
d
20.9 ((H3C)2CH–),
C19H27NO4: C, 68.44; H, 8.16; N, 4.20. Found: C, 68.16; H, 8.22; N, 4.10.
46.0 ((H3C)2CH–), 70.3 (Cbenzylic), 98.2 (C-2), 128.3 (C-6), 129.3 (C-4),
129.4 (C-5), 139.4 (C-3), 139.6 (C-1), 155.0 (NC]O); IR (ATR) 3070,
3060, 2982, 2964, 2925, 2872, 1692, 1567, 1534, 1471, 1446, 1425,
6.3.4. (E)-N,N-Diisopropylcarbamic acid 2-(4-hydroxy-but-2-enyl)-
benzyl ester (21)
1377 cmꢀ1
;
MS (EI, 70 eV) m/z (%) 361 (2) [M]þ, 346 (9)
a,b-Unsaturated ester 20 (47 mg, 0.14 mmol) was dissolved in
[(MꢀCH3)]þ, 302 (21), 260 (3) [(MꢀNiPr2)]þ, 234 (45) [(MꢀI)]þ, 216
(100) [(MꢀOCb)]þ, 144 (8) [OCb]þ, 128 (13) [Cb]þ, 90 (25) [C7H6]þ.
Anal. Calcd for C14H21INO2: C, 46.42; H, 5.84; N, 3.87. Found: C,
46.65; H, 5.45; N, 3.77.
dry THF and the solution was cooled down to ꢀ78 ꢁC. DIBAL-H
(0.35 mL of a 1 M solution in toluene, 0.35 mmol) was slowly added
and the reaction mixture was stirred until the starting material was
fully consumed (2 h, TLC control). Methanol of 2 mL were carefully
added, followed by 2 mL of water before the reaction mixture was
allowed to warm to rt slowly. At rt 5 mL of TBME were used for
dilution and 2 N HCl were added until the solution became clear.
The phases were separated and the organic layer was extracted
with TBME (3ꢂ10 mL). The combined organic layers were dried
over MgSO4 and concentrated in vacuo. Flash chromatography on
silica gel (E/P¼1:1) yielded allyl alcohol (E)-21 (36 mg, 84%) as
colorless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.13 (E/P¼1:1); tR 21.7 min
6.3.2. N,N-Diisopropylcarbamic acid (2-tributylstannyl-benzyl)
ester (19)
In a flame-dried round bottom flask, carbamate 18 (1.81 g,
5.00 mmol) was dissolved in 20 mL of dry THF. The solution was
cooled to ꢀ40 ꢁC and isopropyl-magnesium chloride (2.5 mL of
a 2 M solution in THF, 5.00 mmol) was added. When TLC shows
complete iodo-magnesium exchange, tributyltin chloride (3.26 g,
10.00 mmol) was added and the reaction was allowed to warm to
rt. Methanol (5 mL) and water (10 mL) were added and the
resulting suspension was further diluted with 10 mL of TBME. The
phases were separated, the aqueous phase was extracted with
TBME (3ꢂ20 mL), and the combined organic layers were washed
with brine, dried over MgSO4, and concentrated in vacuo. Purifi-
cation of the crude product by flash chromatography (E/P¼1:20)
yielded 2.07 g (79%) of 19 as colorless liquid. Rf 0.81 (E/P¼1:1); tR
(HP 5); 1H NMR (300 MHz, CDCl3)
d
1.14 (d, 3J¼6.8 Hz, 12H,
(H3C)2CH–),1.91 (brps-s,1H, OH), 3.39 (dd, 3J¼6.4 Hz, 4J¼0.9 Hz, 2H,
–CH2CH]CHCH2O–), 3.85 (ps-s, 2H, (H3C)2CH–), 4.02 (ddd, 3J¼5.9,
2.5 Hz, 4J¼1.2 Hz, 2H, –CH2CH]CHCH2O–), 5.09 (s, 2H, Hbenzylic),
5.56 (dtd, 3J¼5.9, 15.3 Hz, 4J¼1.2 Hz, 1H, –CH2–CH]CHCH2O–), 5.76
(dtd, 3J¼15.3, 6.4 Hz, 4J¼1.2 Hz, 1H, –CH2CH]CHCH2O–), 7.12 (dd,
3J¼7.1 Hz, 4J¼2.0 Hz, 1H, H-3), 7.16 (ddd, 3J¼3J¼7.0 Hz, 4J¼2.0 Hz,
1H, H-5), 7.20 (ddd, 3J¼7.1, 7.0 Hz, 4J¼1.9 Hz, 1H, H-4), 7.30 (dd, 1H,
20.9 min (HP 5); 1H NMR (300 MHz, CDCl3)
d
0.85 (t, 3J¼7.0 Hz, 9H,
3J¼7.0 Hz, 4J¼1.9 Hz, H-6); 13C NMR (75 MHz, CDCl3)
d 20.8
H3CCH2CH2CH2–), 1.01–1.13 (m, 6H, H3CCH2CH2CH2–), 1.19 (d,
3J¼6.3 Hz, 12H, (H3C)2CH–), 1.23–1.38 (m, 6H, H3CCH2CH2CH2–),
1.44–1.62 (m, 6H, H3CCH2CH2CH2–), 3.85 (ps-s, 2H, (H3C)2CH–),
4.98 (s, 2H, Hbenzylic), 7.18 (ddd, 3J¼7.7, 7.4 Hz, 4J¼1.4 Hz, 1H, H-5),
7.25 (ddd, 3J¼3J¼7.4 Hz, 4J¼1.6 Hz, 1H, H-4), 7.39–7.46 (m, 2H, H-3,
((H3C)2CH–), 35.5 (–CH2CH]CH–CH2O–), 45.7 ((H3C)2CH–), 63.5
(Cbenzylic), 64.1 (–CH2CH]CHCH2O–), 126.6, 128.2, 129.1, 129.7,
130.6 (–CH2CH]CH–CH2O–, C-3, C-4, C-5, C-6), 135.0 (C-2), 138.1
(C-1), 155.3 (NC]O); IR (ATR) 3431, 3067, 3033, 2997, 2970, 2934,
2874, 1680, 1605, 1477, 1439, 1369 cmꢀ1; HRMS (ESI): calcd for
H-6); 13C NMR (75 MHz, CDCl3)
d
10.3 (H3CCH2CH2CH2–), 13.5
C
18H27NO3: m/z 328.1883 [MþNa]þ, found: m/z 328.1887 [MþNa]þ.
(H3CCH2CH2CH2–), 21.0 ((H3C)2CH–), 27.1 (H3CCH2–CH2CH2–), 29.0
(H3CCH2–CH2CH2–), 45.9 ((H3C)2CH–), 69.1 (Cbenzylic), 127.1, 128.3,
128.6 (C-4 to C-6), 136.6 (C-2), 142.1 (C-3), 143.5 (C-1), 155.2
(NC]O). IR (ATR) 3054, 2999, 2957, 2926, 2872, 2854, 1694, 1541,
1464, 1436, 1377, 1367 cmꢀ1; MS (ESI) m/z 526.2698 [MþH]þ. Anal.
Calcd for C26H47NO2Sn: C, 59.56; H, 9.03; N, 2.67. Found: C, 59.78;
H, 9.32; N, 2.72.
6.3.5. (E)-N,N-Diisopropylcarbamic acid 2-[4-(tert-butyl-
dimethylsilanyloxy)-but-2-enyl]-benzyl ester (22)
Allyl aclcohol (E)-21 (360 mg, 1.18 mmol) was dissolved in
5.0 mL of dry THF. Triethylamine (0.48 g, 4.13 mmol) and a catalytic
amount of DMAP were added at rt. The mixture was stirred until it
became clear. After cooling to 0 ꢁC, tert-butyl-dimethylsilyl chloride
(214 mg, 1.42 mmol) was added and the reaction mixture was
stirred for 12 h at rt. Dilution by TBME (10 mL) was followed by
addition of water (10 mL). The phases were separated and the
aqueous one was extracted with TBME (3ꢂ10 mL). The combined
organic layers were dried over Na2SO4 and concentrated in vacuo.
Purification by flash chromatography yielded silyl ether (E)-22
(334 mg, 67%) as colorless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.72
6.3.3. (E)-4-{2-[(N,N-Diisopropylcarbamoyloxy)-methyl]-phenyl}-
but-2-enoic acid methyl ester (20)
Pd2(dba)3 (457 mg, 0.50 mmol) was suspended in 10.0 ml of dry
DMF in a flame-dried Schlenk tube under argon atmosphere. trans-
4-Bromo-crotonic acid methyl ester (1.34 g, 7.50 mmol) was added
and the mixture was stirred for 30 min. Then, stannane 19 (2.62 g,
5.00 mmol) was injected and the stirred reaction mixture was
heated to 60 ꢁC for 60 h (sealed tube conditions). After cooling down
to rt, 10 mL of brine were added, followed by 10 mL of TBME. The
organic layer was separated and the aqueous one was extracted with
TBME (3ꢂ15 mL). The combined organic phases were dried over
MgSO4 and concentrated in vacuo. Flash chromatography on silica
gel (E/P¼1:6/1:1) afforded pure ester (E)-20 (1.43 g, 86%) as col-
orless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.59 (E/P¼1:1); tR 20.2 min (HP
(E/P¼1:1), tR 21.8 min (HP 5); 1H NMR (300 MHz, CDCl3)
d 0.00 (s,
6H, (H3C)3C(CH3)2Si–), 0.84 (s, 9H, (H3C)3C(CH3)2Si–), 1.16 (d, 3J¼
6.6 Hz, 12H, (H3C)2CH–), 3.41 (dd, 3J¼6.4 Hz, 4J¼1.3 Hz, 2H,
–CH2CH]CHCH2O–), 3.88 (ps-s, 2H, (H3C)2CH–), 4.09 (dd,
3J¼5.2 Hz, 4J¼1.4 Hz, 2H, –CH2CH]CHCH2O–), 5.10 (s, 2H, Hbenzylic),
5.49 (tdt, 3J¼15.4, 5.2 Hz, 4J¼1.3 Hz, 1H, –CH2CH]CHCH2O–), 5.76
(tdt, 3J¼5.2, 6.4 Hz, 4J¼1.4 Hz, 1H, –CH2–CH]CHCH2O–), 7.12–7.26
(m, 3H, H-3 to H-5), 7.32 (dd, 3J¼7.4 Hz, 4J¼1.8 Hz, 1H, H-6); 13C
5); 1H NMR(300 MHz, CDCl3)
d
1.13 (brd, 3J¼7.3 Hz,12H, (H3C)2CH–),
NMR (75 MHz, CDCl3)
d
ꢀ5.4 ((H3C)3C(CH3)2Si–), 18.1 ((H3C)3C–
3.56 (dd, 3J¼6.6 Hz, 4J¼1.7 Hz, 2H, –CH2CH]CH–), 3.64 (s, 3H,
–OCH3), 3.83 (ps-s, 2H, (H3C)2CH–), 5.05 (s, 2H, Hbenzylic), 5.66 (dt,
3J¼15.8 Hz, 4J¼1.7 Hz, 1H, –CH2CH]CH–), 7.05 (dt, 3J¼15.8, 6.6 Hz,
1H, –CH2CH]CH–), 7.10 (dd, 3J¼5.8 Hz, 4J¼2.5 Hz, 1H, H-6), 7.16–
(CH3)2Si–), 21.0 ((H3C)2CH–), 25.8 ((H3C)3C(CH3)2Si–), 35.0
(–CH2CH]CHCH2O–), 45.8 ((H3C)2CH–), 63.6 (–CH2CH]CHCH2O–),
64.2 (Cbenzylic), 126.3 (–CH2CH]CH–CH2O–), 128.1 (C-5), 128.7
(C-6), 129.2 (C-4), 129.5 (C-3), 130.9 (–CH2CH]CHCH2O–), 134.8 (C-
2),138.6 (C-1),155.3 (NC]O); IR (ATR) 3067, 2957, 2929, 2872, 2856,
1696, 1670, 1654, 1616, 1559, 1464, 1437, 1377 cmꢀ1; MS (ESI) m/z
442.2745 [MþNa]þ. Anal. Calcd for C24H41NO3Si: C, 68.69; H, 9.85; N,
3.34. Found: C, 68.52; H, 10.06; N, 3.20.
7.27 (m, 2H, H-4, H-5), 7.64 (dd, 3J¼6.6 Hz, 4J¼2.6 Hz, 1H, H-3); 13
C
NMR (75 MHz, CDCl3) d 20.7 ((H3C)2CH–), 34.9 (–CH2CH]CH–), 45.8
((H3C)2CH–), 51.4 (–OCH3), 64.2 (Cbenzylic), 122.0 (–CH2CH]CH–),
127.0 (C-4), 128.5 (C-3), 129.8 (C-5), 130.0 (C-6), 135.0 (C-1), 136.2

9130
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
6.3.6. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid {2-[4-(tert-butyl-
dimethylsilanyloxy)-but-2-enyl]-phenyl}-tributylstannyl-methyl
ester (23)
7.00–7.08 (m, 2H, H-3, H-5), 7.18 (ddd, 3J¼7.0, 7.7 Hz, 4J¼1.6 Hz, 1H,
H-4), 7.24 (dd, 3J¼7.8 Hz, 4J¼1.6 Hz, 1H, H-6); 13C NMR (100 MHz,
CDCl3)
d 10.1 (H3CCH2CH2CH2–), 13.6 (H3CCH2CH2CH2–), 20.9
Silyl ether 22 (267 mg, 0.62 mmol) and bis(oxazoline) (ꢀ)-(S,S)-
27 (300 mg, 0.93 mmol) were dissolved in 5 mL of dry diethyl ether
in a flame-dried round bottom flask under argon atmosphere. This
solution was cooled to ꢀ78 ꢁC and sec-butyllithium (0.76 mL,
1.22 M, 0.93 mmol) was added slowly. The reaction mixture was
stirred at this temperature for 2.5 h before tributyltin chloride
(303 mg, 0.93 mmol) was injected. Stirring was continued for 3 h at
ꢀ78 ꢁC. Then 1.0 mL of methanol, 1.0 mL of water, and 1.0 mL of 2 N
HCl were added, and the mixture was allowed to warm to rt. Fur-
ther dilution with TBME (10 mL) and water (10 mL) was followed by
separation of phases and extraction of the aqueous phase with
TBME (3ꢂ10 mL). The combined organic layers were washed with
satd NaHCO3 and dried over MgSO4 prior to concentration in vacuo.
Flash chromatography on silica gel (E/P¼1:30) afforded stannane
((H3C)2CH–), 27.4 (H3CCH2CH2CH2–), 28.8 (H3CCH2–CH2CH2–), 36.2
(–CHAHBCH]CHCH2O–), 46.0 ((H3C)2CH–), 63.8 (–CHAHBCH]CH-
CH2O–), 70.8 (Cbenzylic), 124.6 (CHAHB–CH]CHCH2O–), 124.9 (C-5),
126.7 (C-6), 129.5 (C-4), 130.7 (C-3), 130.9 (CHAHB–CH]CHCH2O–),
132.6 (C-2), 142.2 (C-1), 155.2 (NC]O); IR (ATR) 3426, 3023, 2997,
2971, 2939, 2879, 2843, 1734, 1684, 1474,1464,1437, 1369 cmꢀ1; MS
(ESI) m/z 618.2946 [MþNa]þ. Anal. Calcd for C30H53NO3Sn: C, 60.61;
H, 8.99; N, 2.36. Found: C, 60.98; H, 8.81; N, 2.18.
6.3.8. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid [2-(4-bromo-but-
2-enyl)-phenyl]-tributylstannyl-methyl ester (25)
Allyl alcohol 24 (105 mg, 0.19 mmol) was dissolved in 5 mL of
dry dichloromethane. Tetrabromomethane (79 mg, 0.23 mmol)
was added and the mixture was cooled to 0 ꢁC before triphenyl-
phosphin (76 mg, 0.29 mmol) was added portion wise. The reaction
mixture was stirred for 1 h at 0 ꢁC. Diethyl ether (30 mL) was added
and the resulting suspension was stirred for additional 30 min and
thereby warmed to rt. The residue was filtered through a pad of
silica gel and the filtrate was concentrated in vacuo. Purification by
flash chromatography afforded allyl bromide derivative (ꢀ)-(S)-(E)-
(ꢀ)-(S)-(E)-23 (425 mg, 95%) as colorless liquid, E/Zꢃ98:2 (1H
20
NMR). Rf¼0.85 (E/P¼1:1); tR 24.7 minþdecomposition (HP 5); [
a]
D
ꢀ54.4 (c 1.02, CHCl3), 97% ee; 1H NMR (300 MHz, CDCl3)
d 0.00 (s,
6H, (H3C)3C(CH3)2Si–), 0.76 (t, 3J¼7.6 Hz, 9H, H3CCH2CH2CH2–),
0.84 (s, 9H, (H3C)3C(CH3)2Si–), 1.08–1.34 (m, 18H, H3CCH2CH2CH2–),
1.17 (d, 3J¼7.0 Hz, 12H, (H3C)2CH–), 3.13 (dd, 2J¼15.8 Hz, 3J¼6.4 Hz,
1H, –CHAHBCH]CHCH2O–), 3.25 (dd, 3J¼6.4 Hz, 2J¼15.8 Hz, 1H,
–CHAHBCH]CHCH2O–), 3.91 (sept, 3J¼7.0 Hz, 2H, (H3C)2CH–), 4.11
(dd, 3J¼5.0 Hz, 4J¼1.4 Hz, 2H, –CHAHB–CH]CHCH2O–), 5.55 (tdt,
3J¼15.4, 5.0 Hz, 4J¼1.4 Hz, 1H, –CHAHB–CH]CHCH2O–), 5.76 (s, 1H,
25 (92 mg, 74%) as colorless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.71
20
(E/P¼1:1); [
a
]
ꢀ62.4 (c 1.00, CHCl3), 97% ee; 1H NMR (400 MHz,
D
CDCl3)
d
0.82 (t, 3J¼7.1 Hz, 9H, H3CCH2CH2CH2–), 1.14–1.41 (m, 18H,
H3CCH2CH2–CH2–), 1.23 (d, 3J¼6.8 Hz, 12H, (H3C)2CH–), 3.23 (dd,
2J¼16.1 Hz, 3J¼7.1 Hz, 1H, –CHAHB–CH]CHCH2Br), 3.34 (dd,
3J¼6.5 Hz, 2J¼16.1 Hz, 1H, –CHAHBCH]CH–CH2Br), 4.95 (sept,
3J¼6.8 Hz, 2H, H-8), 4.96 (d, 3J¼7.4 Hz, 2H, –CHAHBCH]CHCH2Br),
5.75 (tdt, 3J¼15.2, 7.6 Hz, 4J¼1.3 Hz, 1H, –CHAHBCH]CH–CH2Br),
5.80 (s, 1H, Hbenzylic), 5.90–5.98 (m, 1H, –CHAHB–CH]CHCH2Br),
7.02–7.09 (m, 2H, H-3, H-5), 7.19 (ddd, 3J¼6.0, 7.6 Hz, 4J¼2.7 Hz, 1H,
H-4), 7.28 (ps-d, 3J¼8.0 Hz, 1H, H-6); 13C NMR (100 MHz, CDCl3)
H
benzylic), 5.77 (tdt, 3J¼15.4 Hz, 4J¼1.4 Hz, 3J¼6.4 Hz, 1H,
–CHAHBCH]CHCH2O–), 6.97 (dd, 3J¼7.4 Hz, 4J¼1.4 Hz, 1H, H-3),
7.03 (ddd, 3J¼7.6, 7.5 Hz, 4J¼1.4 Hz, 1H, H-5), 7.11 (ddd, 3J¼7.4,
7.6 Hz, 4J¼1.2 Hz, 1H, H-4), 7.22 (dd, 3J¼7.5 Hz, 4J¼1.2 Hz, 1H, H-6);
13C NMR (75 MHz, CDCl3)
d
ꢀ5.4 ((H3C)3C(CH3)2Si–), 10.5
(H3CCH2CH2CH2–), 13.4 (H3CCH2CH2CH2–), 18.1 ((H3C)3C–(CH3)2Si–
), 21.0 ((H3C)2CH–), 25.8 ((H3C)3C(CH3)2Si–), 27.4 (H3CCH2CH2CH2–
), 28.6 (H3CCH2CH2CH2–), 35.0 (–CHAHBCH]CHCH2O–), 45.5
((H3C)2CH–), 63.6 (–CHAHBCH]CHCH2O–), 71.8 (Cbenzylic), 124.6
(–CHAHB–CH]CHCH2O–), 124.7 (C-5), 126.3 (C-6), 128.4 (C-4),
128.7 (C-3), 131.3 (–CHAHBCH]CHCH2O–), 133.5 (C-2), 141.1 (C-1),
155.4 (NC]O); IR (ATR) 3067, 2957, 2926, 2872, 2855, 1679, 1600,
1501,1463, 1442,1433, 1378 cmꢀ1; MS (ESI) m/z 732.3801 [MþNa]þ.
Anal. Calcd for C36H67NO3SiSn: C, 61.01; H, 9.53; N, 1.98. Found: C,
60.78; H, 9.37; N, 1.84.
d
10.5 (H3CCH2CH2CH2–), 13.5 (H3CCH2CH2CH2–), 21.0 ((H3C)2CH–),
27.5 (H3CCH2–CH2CH2–), 28.9 (H3CCH2–CH2CH2–), 32.9 (–CHAHB–
CH]CHCH2Br), 35.1 (–CHAHB–CH]CHCH2Br), 45.8 ((H3C)2CH–),
71.6 (Cbenzylic), 125.0 (–CHAHBCH]CH–CH2Br), 125.1 (C-5),
126.7 (C-6), 128.0 (C-4), 129.0 (C-3), 132.6 (C-2), 133.8
(–CHAHBCH]CHCH2Br), 141.4 (C-1), 155.4 (NC]O); IR (ATR) 3066,
2957, 2925, 2871, 2853, 1679, 1600, 1483, 1478, 1462, 1438,
1377 cmꢀ1; MS (ESI) m/z 680.2092 [MþNa]þ. Anal. Calcd for
C30H52BrNO2Sn: C, 54.81; H, 7.97; N, 2.13. Found: C, 55.04; H, 8.16;
6.3.7. (þ)-(S)-(E)-N,N-Diisopropylcarbamic acid 1-[2-(4-hydroxy-
but-2-enyl)-phenyl]-1-tributylstannyl-methyl ester (24)
N, 2.03.
Stannylated silyl ether 23 (212 mg, 0.30 mmol) was dissolved in
a mixture of 2 mL THF and 3 mL diethyl ether. The solution was
cooled to 0 ꢁC and tetrabutyl-ammonium chloride (0.9 mL, 1 M
solution in THF, 0.90 mmol) was added. The solution was stirred at
0 ꢁC until TLC-monitoring proved complete conversion of the
starting material. The solution was then diluted with 10 mL of brine
and 5 mL of TBME. The phases were separated, the aqueous one
was extracted with TBME (3ꢂ10 mL), and the combined organic
phases were dried over MgSO4 prior to concentration in vacuo.
Flash chromatography on silica gel afforded pure stannylated allyl
6.3.9. N,N-Diisopropylcarbamic acid (2,3-dihydro-2-vinyl-1H-
inden-1-yl) ester (26)
According to GPA, CuCN (2.5 mg, 0.03 mmol) was suspended in
1 mL of dry toluene and allyl bromide derivative 25 (92 mg,
0.14 mmol) was added. The mixture was stirred for 72 h at 70 ꢁC
under sealed tube conditions. Work-up was performed as outlined
in GPA. The crude product was subjected to flash chromatography
on silica gel (E/P¼1:20) to yield separately trans-26 (17 mg, 42%)
and cis-26 (17 mg, 42%).
(ꢀ)-(S,S)-26 (trans-26): Rf 0.48 (E/P¼1:4); tR 16.61 min (HP 5);
20
alcohol (þ)-(S)-(E)-24 (145 mg, 81%) as colorless liquid, E/Zꢃ98:2
21.12 min (HP 1701); [
a
]
D
ꢀ65.1 (c 0.32, CHCl3); HPLC: CHIRA-
20
(1H NMR). Rf 0.36 (E/P¼1:1); [
a
]
D
þ25.5 (c 1.00, CHCl3); HPLC:
GROM 1 (2ꢂ250 mm), H/iPrOH¼1000:1, 0.3 mL minꢀ1
, l 210 nm,
Chiralcel AD-H (4.6ꢂ250 mm), H/iPrOH¼200:1, 1.0 mL minꢀ1
,
l
tR(ꢀ) 11.1 min, tR(þ) 12.6 min, 98% ee; 1H NMR (300 MHz, CDCl3)
210 nm, tR(ꢀ) 31.1 min, tR(þ) 38.8 min, 97% ee. 1H NMR (400 MHz,
d
1.14 (d, 3J¼6.9 Hz, 6H, H-9), 1.17 (d, 3J¼6.9 Hz, 6H, H-90), 2.73 (dd,
CDCl3)
d
0.76 (t, 3J¼7.4 Hz, 9H, H3CCH2CH2CH2–), 1.13–1.44 (m, 30H,
2J¼18.7 Hz, 3J¼5.6 Hz, 1H, HA-10), 3.06 (dddt, 3J¼6.7, 7.8, 7.6 Hz,
4J¼1.0 Hz, 1H, H-11), 3.10 (dd, 2J¼18.7 Hz, 3J¼7.8 Hz, 1H, HB-10),
3.65 (ps-s, 1H, H-8), 4.15 (ps-s, 1H, H-80), 5.03 (ddd, 2J¼1.6 Hz,
3J¼10.3 Hz, 4J¼1.0 Hz, 1H, Hcis-13), 5.12 (ddd, 2J¼1.6 Hz, 3J¼17.2 Hz,
4J¼1.0 Hz, 1H, Htrans-13), 5.96 (ddd, 3J¼17.2, 10.3, 7.6 Hz, 1H, H-12),
6.04 (d, 1H, H-1), 7.11–7.23 (m, 3H, H-4, H-5, H-6), 7.28 (ps-d,
(H3C)2CH–, H3CCH2CH2CH2–), 2.45 (t, 3J¼5.7 Hz, 1H, OH), 3.20 (dd,
2J¼16.0 Hz, 3J¼5.1 Hz, 1H, –CHAHBCH]CHCH2O–), 3.27 (dd,
2J¼16.0 Hz, 3J¼7.0 Hz, 1H, –CHAHBCH]CHCH2O–), 3.83 (ps-s, 1H,
(H3C)2CH–), 3.99–4.13 (m, 3H, (H3C)2CH–, –CHAHBCH]CHCH2O–),
5.66 (dtd, 3J¼15.4, 6.3 Hz, 4J¼1.3 Hz, 1H, –CHAHBCH]CH–CH2O),
5.76–5.84 (m, 1H, –CHAHBCH]CH–CH2O), 6.13 (s, 1H, Hbenzylic),
3J¼6.7 Hz,1H, H-3); 13C NMR (75 MHz, CDCl3)
d
21.2 (C-9, C-90), 35.9

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9131
(C-10), 45.8 (C-8, C-80), 51.3 (C-11), 81.8 (C-1), 115.6 (C-13), 124.5 (C-
6.4.2. N,N-Diisopropylcarbamic acid 6-tributylstannyl-
4), 124.9 (C-3), 126.7 (C-5), 128.2 (C-6), 138.9 (C-12), 141.7(7) (C-7),
141.7(9) (C-2), 155.8 (NC]O); IR (ATR) 3076, 2997, 2969, 2932,
2874, 2853, 1687, 1643, 1478, 1462, 1433, 1368 cmꢀ1; HRMS (ESI):
calcd for C18H25NO2: m/z 310.1778 [MþNa]þ, found: m/z 310.1783
[MþNa]þ.
benzo[1,3]dioxol-5-ylmethyl ester (29)
To a solution of n-butylmagnesium chloride (11.00 mL of an 1 M
solution in THF, 11.00 mmol) in 40 mL of dry THF, n-butyllithium
(13.80 mL of an 1.6 M solution in hexane, 22.00 mmol) was added at
0 ꢁC. The solution is stirred for 10 min before it was cooled to ꢀ78 ꢁC.
Benzyl carbamate 28 (4.05 g, 10.00 mmol), dissolved in 10 mL of dry
THF, was added dropwise and the mixture was stirred for 2 h. Then
tributyltinchloride(7.15 g, 22.00 mmol)wasinjectedand thereaction
was stirred for 4 h during which it was slowly warmed to rt. Work-up
was managed according to the synthesis of stannane 19. Purification
by flash chromatography (E/P¼1:20/1:15) yielded stannane 29
(2.51 g, 44%) as colorless liquid. Rf 0.67 (E/P¼1:1); tR 24.9 min (HP 5).
9
8
8'
N
9'
O
O
3
2
7
1
4
5
11 12
1H NMR (300 MHz, CDCl3)
d
0.84 (t, 3J¼6.9 Hz, 9H, H3CCH2CH2CH2–),
10
6
13
0.99–1.10 (m, 6H, H3CCH2CH2CH2–),1.18 (ps-s,12H, (H3C)2CH–),1.21–
1.35 (m, 6H, H3CCH2CH2CH2–), 1.40–1.56 (m, 6H, H3CCH2CH2CH2–),
3.89 (ps-s, 2H, (H3C)2CH–), 4.93 (s, 2H, Hbenzylic), 5.92 (s, 2H, –CH2–),
(ꢀ)-(S,R)-26 (cis-26): Rf 0.41 (E/P¼1:4); tR 16.59 min (HP 5);
6.86 (s, 1H, H-2), 6.94 (s, 1H, H-5); 13C NMR (75 MHz, CDCl3)
d 10.4
20
21.09 min (HP 1701); [
a]
ꢀ49.2 (c 0.31, CHCl3); HPLC: CHIRA-
D
(H3CCH2CH2CH2–), 13.7 (H3CCH2CH2CH2–), 21.0 ((H3C)2CH–), 27.3
(H3CCH2CH2CH2–), 29.0 (H3CCH2CH2–CH2–), 45.9 ((H3C)2CH–), 69.1
(Cbenzylic),100.7 (–CH2–),109.9 (C-2),114.9 (C-5),134.6 (C-6),137.1 (C-
1), 147.1 (C-3), 148.1 (C-4), 155.3 (NC]O); IR (ATR) 3055, 2957, 2926,
2872, 2854, 1691, 600, 1503, 1477, 1440, 1377 cmꢀ1; MS (ESI) m/z
592.2420 [MþNa]þ. Anal. Calcd for C27H47NO4Sn: C, 57.06; H, 8.33; N,
2.46. Found: C, 56.98; H, 8.47; N, 2.36.
GROM 1 (2ꢂ250 mm), H/iPrOH¼1000:1, 0.3 mL minꢀ1
, l 210 nm,
tR(ꢀ) 13.2 min, tR(þ) 20.4 min, 70% ee; 1H NMR (300 MHz, CDCl3)
d
1.12 (br ps-s, 12H, H-9, H-90), 2.98 (dd, 2J¼12.2 Hz, 3J¼7.2 Hz, 1H,
HB-10), 3.03 (m, 1H, HA-10), 3.27 (dddt, 3J¼6.2 Hz, 3J¼3J¼7.2 Hz,
4J¼1.2 Hz, 1H, H-11), 3.64 (ps-s, 1H, H-8), 4.01 (ps-s, 1H, H-80), 5.03
(ddd, 2J¼1.9 Hz, 3J¼10.3 Hz, 4J¼1.2 Hz, 1H, Hcis-13), 5.13 (ddd,
2J¼1.9 Hz, 3J¼17.3 Hz, 4J¼1.2 Hz, 1H, Htrans-13), 5.89 (ddd, 3J¼7.2,
10.3, 17.3 Hz, 1H, H-12), 6.11 (d, 3J¼6.2 Hz, 1H, H-1), 7.13–7.32 (m,
3H, H-4, H-5, H-6), 7.40 (ps-d, 3J¼7.3 Hz, 1H, H-3); 13C NMR
6.4.3. (E)-4-{6-[(N,N-Diisopropylcarbamoyloxy)-methyl]-
benzo[1,3]dioxol-5-yl}-but-2-enoic acid methyl ester (30)
(75 MHz, CDCl3) d
20.7 (C-9, C-90), 36.2 (C-10), 45.8 (C-8, C-80), 48.0
According to the synthesis of ester 20, stannane 29 (2.27 g,
4.00 mmol) was coupled with trans-4-bromo-crotonic acid methyl
ester (895 mg, 5.00 mmol) using Pd2(dba)3 (366 mg, 0.40 mmol) as
catalyst and dry DMF (10.0 mL) as solvent. Flash chromatography
on silica gel (E/P¼1:6/1:2) afforded ester (E)-30 (1.48 g, 98%) as
colorless oil, E/Zꢃ98:2 (1H NMR). Rf 0.36 (E/P¼1:1); tR 22.8 min (HP
(C-11), 79.1 (C-1), 116.1 (C-13), 124.6 (C-4), 125.7 (C-3), 126.6 (C-5),
128.6 (C-6), 137.2 (C-12), 141.6 (C-7), 142.9 (C-2), 155.3 (NC]O); IR
(ATR) 3076, 2969, 2933, 2875, 1685, 1642, 1477, 1462, 1433,
1368 cmꢀ1
; HRMS (ESI): calcd for C18H25NO2: m/z 310.1778
[MþNa]þ, found: m/z 310.1771 [MþNa]þ.
5); 1H NMR (400 MHz, CDCl3)
d 1.15 (ps-s, 12H, (H3C)2CH–), 3.50
9
(dd, 3J¼6.2 Hz, 4J¼1.8 Hz, 2H, –CH2–CH]CH–), 3.66 (s, 3H, –OCH3),
3.84 (ps-s, 2H, (H3C)2CH–), 4.96 (s, 2H, Hbenzylic), 5.67 (dt,
3J¼15.7 Hz, 4J¼1.8 Hz, 1H, –CH2CH]CH–), 5.91 (s, 2H, –CH2–), 6.59
(s, 1H, H-2), 6.84 (s, 1H, H-5), 7.03 (dt, 3J¼6.2, 15.7 Hz, 1H,
8
8'
N
9'
O
O
3
2
7
1
4
5
–CH2CH]CH–); 13C NMR (100 MHz, CDCl3)
d 20.7 ((H3C)2CH–), 34.6
11 12
(–CH2CH]CH–), 45.6 ((H3C)2CH–), 51.2 (–OCH3), 63.8 (Cbenzylic),
101.0 (–CH2–), 110.0 (C-5), 110.2 (C-2), 121.8 (–CH2CH]CH–), 127.5
(C-1), 130.0 (C-6), 146.5 (C-4), 147.3 (–CH2CH]CH–), 147.6 (C-3),
155.1 (NC]O), 166.7 (C]O); IR (ATR) 3067, 2970, 2902, 2846, 1721,
1684, 1655, 1505, 1488, 1436, 1377, 1369 cmꢀ1; MS (ESI) m/z
400.1731 [MþNa]þ. Anal. Calcd for C20H27NO6: C, 63.64; H, 7.21; N,
3.71. Found: C, 63.61; H, 7.29; N, 3.48.
10
6
13
6.4. Synthesis of indanoles 36
6.4.1. N,N-Diisopropylcarbamic acid 6-iodo-benzo[1,3]dioxol-5-
ylmethyl ester (28)
6.4.4. (E)-N,N-Diisopropylcarbamic acid {1-[6-(4-hydroxybut-2-
enyl)-benzo[1.3]dioxo-5-yl-methyl} ester (31)
According to the synthesis of benzyl carbamate 18, (6-iodo-
benzo[1,3]dioxol-5-yl)-methanol (10.50 g, 38 mmol) was dissolved
in 120 mL of THF and deprotonated by sodium hydride (1.75 g,
43.70 mmol, suspension in mineral oil (60%)). Trapping with N,N-
diisopropylcarbamoyl chloride (7.15 g, 43.70 mmol), work-up, and
purification by flash chromatography on silica gel (E/P¼1:4) affor-
ded benzyl carbamate 28 (10.3 g, 67%) as slightly yellow solid. Rf
0.57 (E/P¼1:1); tR 20.8 min (HP 5); mp 71 ꢁC (E); 1H NMR (300 MHz,
According to the synthesis of allyl alcohol 21, ester 30 (189 mg,
0.50 mmol) was reduced by means of DIBAL-H (1.25 mL of an 1 M
solution in toluene, 1.25 mmol) in 5.0 mL of dry THF at ꢀ78 ꢁC. Flash
chromatographyon silica gel afforded allyl alcohol31 (141 mg, 81%) as
colorless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.07 (E/P¼1:1); 1H NMR
(400 MHz, CDCl3)
d
1.18 (d, 3J¼7.0 Hz, 12H, (H3C)2CH–), 1.88 (ps-s, 1H,
OH), 3.34 (dd, 3J¼6.2 Hz, 4J¼1.2 Hz, 2H, –CH2CH]CHCH2O–), 3.80(ps-
s, 1H, (H3C)2CH–), 3.97 (ps-s, 1H, (H3C)2CH–), 4.06 (dd, 3J¼5.8 Hz,
4J¼1.2 Hz, 2H, –CH2CH]CHCH2O–), 5.02 (s, 2H, Hbenzylic), 5.60 (tdt,
3J¼15.4 Hz, 4J¼1.2 Hz, 3J¼5.8 Hz, 1H, –CH2CH]CHCH2O–), 5.76
(tdt, 3J¼15.4, 6.2 Hz, 4J¼1.2 Hz, 1H, –CH2CH]CHCH2O–), 5.91 (s, 2H,
–CH2–), 6.65 (s,1H, H-5), 6.83 (s,1H, H-2); 13C NMR (100 MHz, CDCl3)
CDCl3)
d
1.20 (d, 3J¼6.9 Hz, 12H, (H3C)2CH–), 3.82 (ps-s, 1H,
(H3C)2CH–), 3.99 (ps-s, 1H, (H3C)2CH–), 5.04 (s, 2H, Hbenzylic), 5.96
(s, 2H, –CH2–), 6.90 (s, 1H, H-2), 7.24 (s, 1H, H-5); 13C NMR (75 MHz,
CDCl3) d 21.0 ((H3C)2CH–), 46.0 ((H3C)2CH–), 70.3 (Cbenzylic), 86.8 (C-
6), 101.7 (–CH2–), 110.0 (C-2), 118.7 (C-5), 132.9 (C-1), 148.2 (C-3),
148.4 (C-4), 155.1 (NC]O); IR (ATR) 3093, 2968, 2933, 2901, 1689,
1663, 1610, 1502, 1477, 1444, 1431, 1412, 1387, 1368 cmꢀ1; MS (ESI)
m/z 428.0329 [MþNa]þ. Anal. Calcd for C15H20INO4: C, 44.46; H,
4.97; N, 3.46. Found: C, 44.30; H, 4.77; N, 3.28.
d
20.7 ((H3C)2CH–), 35.0 (–CH2CH]CHCH2O–), 45.6 ((H3C)2CH–),
63.1 (Cbenzylic), 63.7 (–CH2CH]CHCH2O–), 100.9 (–CH2–), 109.6
(C-2), 109.8 (C-5), 128.1 (–CH2CH]CH–CH2O–), 130.5 (C-7), 130.7
(–CH2CH]CHCH2O–), 132.0 (C-1), 146.0 (C-3), 147.4 (C-4), 155.5

9132
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
(NC]O);IR(ATR)3432, 3034, 2970, 2934,2896,1678,1621,1503,1486,
1442, 1369 cmꢀ1; MS (ESI) m/z 372.1776 [MþNa]þ. Anal. Calcd for
to 0 ꢁC and 0.5 mL of trifluoroacetic acid was added dropwise. The
reaction mixture was stirred over night at 0 ꢁC. When the reaction
was complete (TLC control), the mixture is diluted with 10 mL of
TBME and 5 mL of water, warmed to rt, and the phases were sepa-
rated. The aqueous phase was extracted with TBME (3ꢂ10 mL). The
combined organic phases were washed with satd NaHCO3, dried
over MgSO4, and concentrated in vacuo. Flash chromatography on
C19H27NO4: C, 65.31; H, 7.79; N, 4.01 Found: C, 65.42; H, 8.07; N, 3.75.
6.4.5. (E)-N,N-Diisopropylcarbamic acid {1-[6-(4-triethylsilanyl-
oxy-but-2-enyl)-benzo[1,3]dioxol-5-yl]-methyl} ester (32)
According to the synthesis of silyl ether 22, allyl alcohol 31 (1.05 g,
3.00 mmol), dissolved in 30 mL of dry THF, was treated with tri-
ethylamine (756 mg, 7.50 mmol) and a catalytic amount of DMAP at
0 ꢁC for 10 min. Triethylsilyl chloride (475 mg, 3.15 mmol) was injec-
ted dropwise and the reaction mixture was stirred for 12 h while
warming to rt. Work-up as described in the synthesis of 22 and puri-
fication of the crude product by flash chromatography on silica gel
(E/P¼1.8) afforded silyl ether (E)-32 (1.12 g, 80%) as colorless liquid,
E/Zꢃ98:2 (1H NMR). Rf 0.69 (E/P¼1:1); tR 24.9 min (HP 5); 1H NMR
silica gel (E/P¼1:3) afforded (ꢀ)-(S)-(E)-34 (264 mg, 61%) as color-
20
less liquid, E/Zꢃ98:2 (1H NMR). Rf 0.33 (E/P¼1:1); [
a]
ꢀ6.9 (c 0.51,
D
CHCl3); HPLC: Chiralcel AD-H (4.6ꢂ250 mm), H/iPrOH¼200:1,
0.3 mL minꢀ1
,
l
210 nm, tR(þ) 63.2 min, tR(ꢀ) 77.8 min, 97% ee; 1H
NMR (400 MHz, CDCl3)
d
0.85 (t, 3J¼6.8 Hz, 9H, H3CCH2CH2CH2–),
1.16–1.48 (m, 18H, H3CCH2CH2CH2–), 1.23 (d, 3J¼6.7 Hz, 12H,
(H3C)2CH–), 2.49 (ps-s, 1H, OH), 3.12 (ddd, 2J¼15.8 Hz, 3J¼4.8 Hz,
4J¼1.1 Hz, 1H, –CHAHBCH]CHCH2O–), 3.20 (dd, 3J¼6.8 Hz,
2J¼15.8 Hz, 1H, –CHAHBCH]CHCH2O–), 3.86 (ps-s, 1H, (H3C)2CH–),
4.05 (ps-s,1H, (H3C)2CH–), 4.07 (m, 2H, –CHAHBCH]CHCH2O–), 5.67
(tdt, 3J¼15.4, 6.1 Hz, 4J¼1.1 Hz, 1H, –CHAHBCH]CHCH2O–), 5.76
(m, 1H, –CHAHBCH]CHCH2O–), 5.90 (s, 2H, –CH2–), 6.02 (s, 1H,
(400 MHz, CDCl3)
d
0.59 (q, 3J¼8.1 Hz, 6H, H3CCH2–), 0.94 (t, 3J¼8.1 Hz,
9H, H3CCH2–), 1.18 (d, 3J¼6.2 Hz, 12H, (H3C)2–CH–), 3.35 (dd,
3J¼6.5 Hz, 4J¼1.3 Hz, 2H, –CH2CH]CH–CH2O–), 3.80 (ps-s, 1H,
(H3C)2CH–), 3.99 (ps-s, 1H, (H3C)2CH–), 4.11 (dd, 3J¼5.3 Hz, 4J¼1.3 Hz,
2H, –CH2CH]CHCH2O–), 5.01 (s, 2H, Hbenzylic), 5.53 (tdt, 3J¼15.3,
5.3 Hz, 4J¼1.3 Hz, 1H, –CH2CH]CHCH2O–), 5.75 (tdt, 3J¼15.3, 6.5 Hz,
4J¼1.3 Hz, 1H, –CH2CH]CH–CH2O–), 5.92 (s, 2H, –CH2–), 6.67 (s, 1H,
H
benzylic), 6.59 (s, 1H, H-5), 6.75 (s, 1H, H-2); 13C NMR (100 MHz,
CDCl3) 10.1 (H3CCH2CH2CH2–), 13.5 (H3CCH2CH2CH2–), 21.1
d
((H3C)2CH–), 27.4 (H3CCH2–CH2CH2–), 28.7 (H3CCH2–CH2CH2–), 35.9
(–CHAHBCH]CHCH2O–), 46.0 ((H3C)2CH–), 63.6 (–CHAHBCH]CH-
CH2O–), 70.6 (Cbenzylic), 100.5 (–CH2–), 105.3 (C-2), 109.7 (C-5), 125.7
(–CHAHBCH]CHCH2O–), 130.6 (C-6), 130.8 (–CHAHBCH]CHCH2O–),
135.7 (C-1), 144.8 (C-3), 146.5 (C-4), 155.2 (NC]O); IR (ATR) 3432,
H-5), 6.84 (s,1H, H-2); 13C NMR (100 MHz, CDCl3)
d 4.2 (H3CCH2–), 6.4
(H3CCH2–), 20.8 ((H3C)2CH–), 34.6 (–CH2CH]CHCH2O–), 45.4
((H3C)2CH–), 63.2 (–CH2CH]CHCH2O–), 63.9 (Cbenzylic),100.7(–CH2–),
109.7 (C-2), 109.8 (C-5), 127.9 (–CH2CH]CHCH2O–),129.2 (C-6),130.7
(–CH2CH]CHCH2O–), 132.6 (C-1), 145.8 (C-3), 147.3 (C-4), 155.5
(NC]O); IR (ATR) 3037, 2957, 2936, 2911, 2876,1689,1622,1504,1487,
1461, 1441, 1376, 1368 cmꢀ1; MS (ESI) m/z 486.2640 [MþNa]þ. Anal.
Calcd for C25H41NO5Si: C, 64.76; H, 8.91; N, 3.02. Found: C, 64.42; H,
9.05; N, 2.89.
3065, 2956, 2923, 2871, 2854,1676,1617,1504,1483,1436,1376 cmꢀ1
;
MS (ESI) m/z 662.2845 [MþNa]þ. Anal. Calcd for C31H53NO5Sn: C,
58.32; H, 8.37; N, 2.19. Found: C, 58.45; H, 8.42; N, 2.02.
6.4.8. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid [6-(4-bromo-but-
2-enyl)-benzo[1,3]dioxol-5-yl]-tributylstannyl-methyl ester (35)
According to the synthesis of allyl bromide 25, allyl alcohol 34
(254 mg, 0.40 mmol) was converted into allyl bromide derivative 35
using tetrabromomethane (166 mg, 0.50 mmol) and triphenyl-
phosphine (157 mg, 0.60 mmol). Flash chromatography on silica
6.4.6. (ꢀ)-(S)-(E)-Diisopropylcarbamic acid tributylstannyl-[6-(4-
triethylsilanyloxy-but-2-enyl)-benzo[1,3]dioxol-5-yl]-methyl ester (33)
Asymmetricstannylationwasachieveddaccordingtotheprotocol
used for the synthesis of stannane 23dusing silyl ether 32 (464 mg,
1.00 mL), dissolved in 5 mL of dry diethyl ether, bis(oxazoline) 27
gel (E/P¼1:15) afforded (ꢀ)-(S)-(E)-35 (210 mg, 75%) as colorless
20
(386 mg, 1.20 mmol), sec-butyllithium (0.98 mL of
a
1.22 M,
liquid, E/Zꢃ98:2 (1H NMR). Rf 0.73 (E/P¼1:1); [
a
]
ꢀ12.4 (c 0.50,
D
1.20 mmol), and tributyltin chloride (422 mg, 1.30 mmol). Flash
CHCl3), 97% ee; 1H NMR (400 MHz, CDCl3)
d
0.78 (t, 3J¼7.4 Hz,
chromatography on silica gel (E/P¼1:20) was used for purification.
9H, H3CCH2CH2CH2–), 1.09–1.62 (m, 18H, H3CCH2CH2CH2–), 1.17
(d, 3J¼6.7 Hz, 12H, (H3C)2CH–), 3.10 (dd, 2J¼15.8 Hz, 3J¼6.7 Hz,
1H, –CHAHB–CH]CHCH2Br), 3.21 (ps-dd, 2J¼15.8 Hz, 3J¼6.3 Hz,
1H, –CHAHBCH]CHCH2Br), 3.88 (ps-s, 2H, (H3C)2CH–), 3.90 (dd,
3J¼7.5 Hz, 4J¼0.7 Hz, 2H, –CHAHBCH]CHCH2Br), 5.66 (tdt, 3J¼15.0,
7.4 Hz, 4J¼1.3 Hz, 1H, –CHAHBCH]CHCH2Br), 5.67 (s, 1H, Hbenzylic),
5.77–5.86 (m, 1H, –CHAHBCH]CHCH2Br), 5.84 (s, 2H, –CH2–), 6.52
Stannane (ꢀ)-(S)-(E)-33 (531 mg, 71%) was obtained as colorless liq-
20
uid, E/Zꢃ98:2 (1H NMR). Rf 0.76 (E/P¼1:1); [
a]
D
ꢀ7.5 (c 1.03, CHCl3),
97% ee; 1H NMR (400 MHz, CDCl3)
d
0.58 (q, 3J¼8.0 Hz, 6H, H3CCH2–),
0.81 (t, 3J¼6.9 Hz, 9H, H3CCH2CH2CH2–), 0.93 (t, 3J¼6.9 Hz, 9H,
H3CCH2–), 1.14–1.44 (m, 18H, H3CCH2CH2CH2–), 1.21 (d, 3J¼6.9 Hz,
12H, (H3C)2CH–), 3.10 (dd, 2J¼16.0 Hz, 3J¼6.9 Hz, 1H,
–CHAHBCH]CHCH2O–), 3.23 (ddd, 2J¼16.0 Hz, 3J¼6.4 Hz, 4J¼1.1 Hz,
1H, –CHAHBCH]CHCH2O–), 3.93 (sept, 3J¼6.9 Hz, 2H, H-8), 4.13 (dd,
(s, 1H, H-5), 6.7 (s, 1H, H-2); 13C NMR (100 MHz, CDCl3)
d 10.4
(H3CCH2CH2CH2–), 13.6 (H3CCH2CH2CH2–), 21.1 ((H3C)2CH–), 27.5
(H3CCH2–CH2CH2–), 28.9 (H3CCH2CH2CH2–), 32.8 (–CHAHBCH]
CHCH2Br), 35.0 (–CHAHBCH]CHCH2Br), 46.0 ((H3C)2CH–), 71.5
(Cbenzylic), 100.6 (–CH2), 105.8 (C-2), 109.2 (C-5), 125.9 (C-6), 127.9
(–CHAHBCH]CHCH2Br), 134.0 (–CHAHBCH]CHCH2Br), 135.0 (C-1),
145.1 (C-3), 146.5 (C-4), 155.4 (NC]O); IR (ATR) 3091, 2957, 2924,
3J¼5.5 Hz, J¼1.3 Hz, 2H, –CHAHBCH]CHCH2O–), 5.60 (tdt, 3J¼15.3,
4
5.5 Hz, 4J¼1.1 Hz, 1H, –CHAHBCH]CHCH2O–), 5.73 (s, 1H, Hbenzylic),
5.70–5.79 (m,1H, –CHAHBCH]CHCH2O–), 5.87 (s, 2H, –CH2–), 6.60 (s,
1H, H-5), 6.76 (s,1H, H-2);13C NMR(100 MHz, CDCl3)
d 4.5 (H3CCH2–),
6.7 (H3CCH2–), 10.4 (H3CCH2CH2CH2–), 13.6 (H3CCH2CH2CH2–), 21.0
((H3C)2CH–), 27.5 (H3CCH2CH2CH2–), 28.9 (H3CCH2–CH2CH2–), 35.0
(–CHAHBCH]CHCH2O–), 45.8 ((H3C)2CH–), 63.5 (–CHAHBCH]CH-
CH2O–), 71.7 (Cbenzylic), 100.5 (–CH2–), 105.5 (C-2), 109.0 (C-5), 126.9
(–CHAHB–CH]CHCH2O–),128.9 (C-6),131.3(–CHAHBCH]CH–CH2O–
), 134.8 (C-1), 144.9 (C-3), 146.1 (C-4), 155.4 (NC]O); IR (ATR) 3065,
3018, 2997, 2959, 2936, 2912, 2876, 1692, 1457, 1436, 1368 cmꢀ1; MS
(ESI) m/z 776.3699 [MþNa]þ. Anal. Calcd for C37H67NO5SiSn: C, 59.04;
H, 8.97; N, 1.86. Found: C, 58.95; H, 9.09; N, 1.78.
2872, 2853, 2764, 2723,1678,1618,1504,1482,1464,1436,1376 cmꢀ1
;
MS (ESI) m/z 724.1971 [MþNa]þ. Anal. Calcd for C31H52BrNO4Sn: C,
53.09; H, 7.47; N, 2.00 Found: C, 53.37; H, 7.62; N, 1.94.
6.4.9. N,N-Diisopropylcarbamic acid (6-ethenyl-6,7-dihydro-5H-
indeno-[5,6-d][1.3]dioxo-5-yl) ester (36)
According to GPA, CuCN (3.5 mg, 0.04 mmol) was suspended in
4.0 mL of dry toluene and allyl bromide derivative 35 (175 mg,
0.26 mmol) was added. The mixture was stirred for 72 h at 70 ꢁC
under sealed tube conditions. Work-up was performed as outlined
in GPA. Flash chromatography on silica gel (E/P¼1:6) afforded trans-
36 and cis-36 as an inseparable mixture (51 mg, 60%), trans-36/cis-
36¼1.1:1 (1H NMR).
6.4.7. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid [6-(4-hydroxy-
but-2-enyl)-benzo[1,3]dioxol-5-yl]-tributylstannyl-methyl ester (34)
Silyl ether 33 (511 mg, 0.68 mmol) was dissolved in a mixture
consisting of 3 mL of THF and 3 mL of water. The solution was cooled

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9133
Data for (S,S)-36 (trans-36) and (S,R)-36 (cis-36): Rf 0.70 (E/
4J¼1.4 Hz, 2H, H-1), 5.04 (dd, 2J¼2.3 Hz, 3J¼9.8 Hz, 1H, Htrans-5),
5.17 (dd, 2J¼2.3 Hz, 3J¼16.2 Hz, 1H, Hcis-5), 5.78 (dt, 3J¼5.3, 14.9 Hz,
1H, H-2), 6.24 (ddt, 3J¼14.5, 14.9 Hz, 4J¼1.4 Hz, 1H, H-3), 6.27–6.41
20
P¼1:1); tR 14.15 min (1S,2S) and (1S,2R) (HP 5); [
a
]
ꢀ21.4 (c 0.81,
D
CHCl3), trans-36/cis-36¼1.1:1; HPLC: CHIRA-GROM 2 (2ꢂ250 mm),
H/iPrOH¼1000:1, 0.3 mL minꢀ1
,
l
210 nm, tR
*
(1S,2S
*
)
23.3 min,
(m, 1H, H-4); 13C NMR (75 MHz, CDCl3)
d 4.2 (H3CCH2–), 6.4
tR(1R,2S
*
) 33.0 min, 95% ee; tR
*
(1S,2R
*
) 26.6 min, tR(1R,2R
*
) 41.8 min,
(H3CCH2–), 63.0 (C-1), 116.7 (C-5), 130.7 (C-2), 133.2 (C-3), 136.6 (C-
4); IR (ATR) 3095, 3065, 2955, 2913, 2877, 1726, 1605, 1504, 1459,
1415, 1374 cmꢀ1; HRMS (ESI): calcd for C11H22OSi: m/z 221.1332
[MþNa]þ, 419.2772 [2MþNa]þ, found: m/z 221.1318 [MþNa]þ,
419.2769 [2MþNa]þ.
92% ee; 1H NMR (300 MHz, CDCl3)
d
1.16 (d, 3J¼6.4 Hz, 12H, H-9, H-
3
90 (1S,2S)), 1.21 (d, J¼6.4 Hz, 12H, H-9, H-90, (1S,2R)), 2.67 (dd,
2J¼18.4 Hz, 3J¼10.1 Hz, 1H, HA-11, (1S,2S)), 2.81–2.97 (m, 2H, HB-11
(1S,2R), H-12 (1S,2S)), 3.00–3.14 (m, 2H, HA-11 (1S,2R), HB-11
(1S,2S)), 3.28 (m, 1H, H-12 (1S,2R)), 3.67 (ps-s, 2H, H-8 (1S,2S) and
(1S,2R)), 4.18 (ps-s, 1H, H-80 (1S,2S)), 4.04 (ps-s, 1H, H-80 (1S,2R)),
5.06 (ddd, 2J¼1.9 Hz, 3J¼10.2 Hz, 4J¼1.0 Hz,1H, Hcis-14 (1S,2R)), 5.07
(ddd, 2J¼1.7 Hz, 3J¼10.4 Hz, 1H, 4J¼0.8 Hz, Hcis-14 (1S,2S)), 5.13 (dd,
2J¼1.9 Hz, 3J¼17.2 Hz, 1H, Htrans-14 (1S,2R)), 5.14 (dd, 2J¼1.7 Hz,
3J¼17.2 Hz, 1H, Htrans-14 (1S,2S)), 5.84–5.98 (m, 7H, H-1, H-10, H-13
(1S,2S), H-10, H-13 (1S,2R)), 6.04 (d, 3J¼6.5 Hz, 1H, H-1 (1S,2R)),
6.66 (s, 1H, H-3 (1S,2S)), 6.69 (s, 1H, H-3 (1S,2R)), 6.82 (s, 1H, H-6
6.5.2. (E)-N,N-Diisopropylcarbamic acid 2-(5-triethylsilanyloxy-
pent-3-enyl)-benzyl ester (38)
Firstly, unsaturated silyl ether (E)-37 was dissolved in 5.0 mL of
dry THF and the solution was cooled to 0 ꢁC. A solution of 9-bora-
bicyclo[3.3.1]nonane (10.00 mL of
a 0.5 M solution in THF,
5.00 mmol) was injected slowly and the reaction mixture was kept
stirring for 6 h and finally warmed to rt. The resulting solution was
directly used in the following coupling reaction.
(1S,2S)), 6.91 (s, 1H, H-6 (1S,2R)); 13C NMR (75 MHz, CDCl3)
d 20.6
(C-9 (1S,2R)), 21.6 (C-9 (1S,2S)), 35.7 (C-11 (1S,2S)), 35.9 (C-11
(1S,2R)), 45.3 (C-8, C-80 (1S,2R)), 46.3 (C-8, C-80 (1S,2S)), 48.6 (C-12
(1S,2R)), 51.3 (C-12 (1S,2S)), 79.1 (C-1 (1S,2R)), 81.9 (C-1 (1S,2S)),
Potassium phosphate (955 mg, 4.50 mmol) was weighted into
a Schlenk tube. ortho-Iodo-substituted benzyl carbamate 18 (1.62 g,
4.50 mmol) and Pd(PPh3)4 (156 mg, 0.14 mmol) were added. The solids
were dissolved in 10 mL of dry DMF and the borane-containing THF-
solution was added by transfer cannula. The reaction mixture was
heated to 60 ꢁC and stirred for 32 h (sealed tube). For work-up, the
reaction mixture was cooled to rt, diluted with 10 mL of TBME and
10 mL of water. The phases were separated and the aqueous one was
extracted with TBME (3ꢂ20 mL). The combined organic phases were
dried over MgSO4 and concentrated invacuo. Flash chromatography on
silica gel afforded silylated allyl alcohol (E)-38 (1.62 g, 83%) as colorless
101.4 (C-10 (1S,2S) and (1S,2R)), 104.8(6) (C-3, (1S,2S
(C-3, (1S,2R )), 105.6 (C-6 (1S,2S)), 106.1 (C-6 (1S,2R)), 115.5 (C-14
(1S,2S)), 116.1 (C-14 (1S,2R)), 134.4 (C-7, (1S,2S )), 134.5 (C-7,
(1S,2R )), 135.4 (C-13 (1S,2R)), 136.6 (C-13 (1S,2S)), 137.2
(C-2 (1S,2R )), 138.9 (C-2 (1S,2S )), 146.5 (C-4 (1S,2S )), 146.7 (C-4
(1S,2R )), 148.1 (C-5 (1S,2S )), 148.3 (C-5 (1S,2R )), 155.3 (NC]O
*
)), 104.9(1)
*
*
*
*
*
*
*
*
*
(1S,2S)), 155.8 (NC]O (1S,2R)); IR (ATR) 3078, 2970, 2934, 2880,
2852, 2771, 1682, 1644, 1502, 1474, 1436, 1368 cmꢀ1; MS (ESI) m/z
354.1678 [MþNa]þ. Anal. Calcd for C19H25NO4: C, 68.86; H, 7.60; N,
4.23. Found: C, 68.74; H, 7.43; N, 4.05.
1
liquid, E/Zꢃ98:2 (1H NMR). Rf 0.74 (E/P¼1:1); tR 23.3 min (HP 5); H
NMR (400 MHz, CDCl3)
d
0.60 (q, 3J¼7.8 Hz, 6H, H3CCH2–), 0.95 (t,
3J¼7.8 Hz, 9H, H3CCH2–), 1.19 (ps-s, 12H, (H3C)2CH–), 2.33 (dtd, 3J¼8.2,
6.7 Hz, 4J¼1.1 Hz, 2H, –CH2CH2CH]CHCH2O–), 2.71–2.78 (m, 2H,
–CH2CH2–CH]CHCH2O–), 3.91 (ps-s, 2H, (H3C)2CH–), 4.10 (dd, 3J¼
5.4 Hz, 4J¼1.2 Hz, 2H, –CH2CH2CH]CHCH2O–), 5.15 (s, 2H, Hbenzylic),
5.59 (tdt, 3J¼15.3, 5.4 Hz, 4J¼1.1 Hz, 1H, –CH2CH2CH]CHCH2O–), 5.71
(tdt, 3J¼15.3, 6.7 Hz, 4J¼1.2 Hz, 1H, –CH2CH2CH]CHCH2O–), 7.15–7.31
(m, 3H, H-3, H-4, H-5), 7.32–7.37 (m, 1H, H-6); 13C NMR (100 MHz,
9'
8'
8
N
9
O
O
3
4
2
7
1
O
O
12 13
10
∗
5
11
CDCl3)
d 4.3 (H3CCH2–), 6.4 (H3CCH2–), 20.3 ((H3C)2CH–), 31.9
6
14
(–CH2CH2CH]CHCH2O–), 33.3 (–CH2CH2CH]CHCH2O–), 45.6
((H3C)2CH–), 63.3 (–CH2CH2CH]CHCH2O–), 64.0(Cbenzylic),126.1 (C-5),
128.1 (C-6), 129.3 (C-4), 129.4 (C-3), 129.9 (–CH2CH2CH]CHCH2O–),
130.4 (–CH2CH2CH]CH–CH2O–), 134.5 (C-2), 140.4 (C-1), 155.3
(NC]O); IR (ATR) 3024, 2960, 2933, 2914, 2876, 2855, 1693, 1452,
1439, 1377, 1368 cmꢀ1; MS (ESI) m/z 456.2908 [MþNa]þ. Anal. Calcd
for C25H43NO3Si: C, 69.23; H, 9.99; N, 3.23. Found: C, 68.88; H, 10.13;
N, 3.19.
6.5. Synthesis of tetralines 42
6.5.1. (E)-(Penta-2,4-dienyloxy)-triethylsilane (37)
Lithium aluminum hydride (397 mg, 10.00 mmol) was sus-
pended in 20 mL of dry diethyl ether and cooled to ꢀ15 ꢁC. Penta-
2,4-dienoic acid methyl ester (561 mg, 5.00 mmol) was added
dropwise via syringe. The reaction mixture was stirred for 2 h at
ꢀ15 ꢁC. Ice-water of 5 mL was carefully added. When gassing has
ceased, sulfuric acid (10%) was added carefully and dropwise until
the mixture became clear. The phases were separated and the
aqueous one was extracted with diethyl ether (3ꢂ20 mL), dried
over MgSO4, and carefully concentrated in vacuo (pꢃ930 mbar) to
obtain the crude allyl alcohol.43
6.5.3. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid tributylstannyl-[2-
(5-triethylsilanyloxy-pent-3-enyl)-phenyl]-methyl ester (39)
Asymmetric stannylation was achieveddaccording to the pro-
tocol used for the synthesis of stannane 23dusing silyl ether 38
(434 mg, 1.00 mmol), dissolved in 5 mL of dry diethyl ether,
bis(oxazoline) 27 (386 mg, 1.20 mmol), sec-butyllithium (0.98 mL
of 1.22 M, 1.20 mmol), and tributyltin chloride (424 mg,
1.30 mmol). Flash chromatography on silica gel (E/P¼1:20) affor-
The crude alcohol was directly dissolved again in 30 mL of THF
and the solution was cooled to 0 ꢁC. Triethylamine (1.45 g,
12.5 mmol) and a catalytic amount of DMAP were added and the
mixture was stirred until it became clear. Then, triethylsilyl chlo-
ride (791 mg, 5.25 mmol) was injected portion wise. The reaction
mixture was stirred for 12 h and slowly warmed to rt. Work-up and
rough purification by flash chromatography on silica gel (E/
P¼1:40) afforded unsaturated silane 37 (942 mg) as colorless,
volatile liquid after careful concentration in vacuo (pꢃ700 mbar),
E/Z¼95:5 (1H NMR). Data for (E)-37: Rf 0.75 (E/P¼1:1); tR 9.2 min
ded stannane (ꢀ)-(S)-(E)-39 (480 mg, 66%) as colorless liquid, E/
20
Zꢃ98:2 (1H NMR). Rf 0.75 (E/P¼1:1); [
a
]
D
ꢀ27.6 (c 1.07, CHCl3), 72%
ee; 1H NMR (400 MHz, CDCl3)
d
0.61 (q, 3J¼8.0 Hz, 6H, H3CCH2–),
0.81 (t, 3J¼7.2 Hz, 9H, H3CCH2CH2CH2–), 0.96 (t, 3J¼8.0 Hz, 9H,
H3CCH2–), 1.15–1.41 (m, 18H, H3CCH2CH2CH2–), 1.23 (d, 3J¼7.0 Hz,
12H, (H3C)2CH–), 2.22–2.34 (m, 1H, –CHAHBCHAHBCH]CHCH2O–),
2.34–2.45 (m, 1H, –CHAHBCHAHBCH]CHCH2O–), 2.46–2.53 (m,
1H, –CHAHBCHAHBCH]CHCH2O–), 2.53–2.63 (m, 1H, –CHAHB-
CHAHBCH]CHCH2O–), 3.97 (sept, 3J¼7.0 Hz, 2H, H-8, (H3C)2CH–),
4.11 (dd, 3J¼5.4 Hz, 4J¼1.2 Hz, 2H, –CHAHBCHAHBCH]CHCH2O–),
(HP 5); 1H NMR (300 MHz, CDCl3)
d
0.62 (q, 3J¼7.9 Hz, 6H,
H3CCH2–), 0.96 (t, 3J¼7.9 Hz, 9H, H3CCH2–), 4.21 (dd, 3J¼5.3 Hz,

9134
H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
5.63 (dtd, 3J¼15.1, 5.4 Hz, 4J¼1.2 Hz, 1H, –CHAHBCHAHBCH]CH-
CH2O–), 5.74 (ps-ddt, 3J¼15.1, 6.4 Hz, 4J¼1.2 Hz, 1H, –CHAHBCHAHB–
CH]CHCH2O–), 5.84 (s, 1H, Hbenzylic), 7.02 (ddd, 3J¼3J¼7.3 Hz,
4J¼1.3 Hz,1H, H-5), 7.09 (dd, 3J¼7.8 Hz, 4J¼1.3 Hz,1H, H-3), 7.15 (ddd,
3J¼7.2 Hz, 1H, H-6); 13C NMR (100 MHz, CDCl3)
d 10.4 (H3CCH2–
CH2CH2–), 13.6 (H3CCH2CH2CH2–), 20.9 ((H3C)2CH–), 27.5 (H3CCH2-
CH2CH2–), 28.8 (H3CCH2–CH2CH2–), 31.9 (–CHAHBCHAHBCH]
CHCH2Br), 32.3 (–CHAHBCHAHB–CH]CHCH2Br), 33.2 (–CHAHBCHA-
HB–CH]CHCH2Br), 45.7 ((H3C)2CH–), 71.6 (Cbenzylic), 124.8 (C-5),
126.3 (C-6), 126.9 (C-4), 128.5 (C-3), 134.3 (–CHAHBCHAHB–
CH]CHCH2Br), 135.5 (–CHAHBCHAHBCH]CHCH2Br), 141.2 (C-2),
141.3 (C-1), 155.2 (NC]O); IR (ATR) 3064, 2957, 2924, 2871, 2854,
2759, 2723, 1679, 1631, 1601, 1548, 1464, 1433, 1378, 1369 cmꢀ1; MS
(ESI) m/z 694.2244 [MþNa]þ. Anal. Calcd for C31H54BrNO2Sn: C,
55.46; H, 8.11; N, 2.09. Found: C, 55.38; H, 8.19; N, 1.96.
3J¼7.8, 7.3 Hz, 4J¼1.4 Hz,1H, H-4), 7.26 (ps-d, 3J¼7.3 Hz,1H, H-6); 13
C
NMR (100 MHz, CDCl3)
d 4.5 (H3CCH2–), 6.7 (H3CCH2–), 10.5
(H3CCH2CH2CH2–), 13.6 (H3CCH2CH2CH2–), 21.0 ((H3C)2CH–), 27.5
(H3CCH2CH2CH2–), 28.9 (H3CCH2–CH2CH2–), 32.4 (–CHAHB-
CHAHBCH]CH–CH2O–), 32.6 (–CHAHBCHAHBCH]CHCH2O–), 45.9
((H3C)2CH–), 63.6 (–CHAHBCHAHBCH]CHCH2O–), 71.8 (Cbenzylic),
124.7 (C-5), 124.8 (C-6), 126.2 (C-4), 128.6 (C-3), 129.7 (–CHAHB
-
CHAHBCH]CHCH2O–),130.8 (–CHAHBCHAHB–CH]CHCH2O–),134.9
(C-2), 141.2 (C-1), 155.5 (NC]O); IR (ATR) 3062, 2957, 2931, 2875,
2854, 1680, 1601, 1478, 1462, 1440, 1433, 1377, 1368 cmꢀ1; MS (ESI)
m/z 746.3978 [MþNa]þ. Anal. Calcd for C37H69NO3SiSn: C, 61.49; H,
9.62; N, 1.94. Found: C, 61.46; H, 9.76; N, 1.91.
6.5.6. N,N-Diisopropylcarbamic acid 2-ethenyl-1,2,3,4-tetrahydro-
naphthalen-1-yl ester (42)
According to GPA, CuCN (2.0 mg, 0.02 mmol) was suspended in
2.0 mL of dry toluene and allyl bromide derivative 41 (100 mg,
0.15 mmol) was added. The mixture was stirred for 72 h at 70 ꢁC
under sealed tube conditions. Work-up was performed as outlined
in GPA. Flash chromatography on silica gel (E/P¼1:6) afforded trans-
42 and cis-42 as an inseparable mixture (30 mg, 66%), trans-42/cis-
42¼1.5:1 (1H NMR).
6.5.4. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid [2-(5-hydroxy-
pent-3-enyl)-phenyl]-tributylstannyl-methyl ester (40)
According to the synthesis of allyl alcohol 34, desilylation was
accomplished by dissolving silyl ether 39 (325 mg, 0.45 mmol) in
3 mL THF and 3 mL water and adding 0.5 mL trifluoroacetic acid.
Work-up and purification by flash chromatography on silica gel (E/
Data for trans-42 ((1S,2S)-42) and cis-42 ((1S,2R)-42): Rf 0.67
20
(E/P¼1:1); tR 17.6 min (1S,2R), 17.7 min (1S,2S) (HP 5); [
a
]
ꢀ38.5
D
P¼1:8) afforded allyl alcohol derivative (ꢀ)-(S)-(E)-40 (158 mg, 65%)
(c 0.81, CHCl3) trans-42/cis-42¼1.5:1; HPLC: CHIRA-GROM
1
20
as colorless liquid, E/Zꢃ98:2 (1H NMR). Rf 0.27 (E/P¼1:1); [
a]
D
ꢀ46.1
(2ꢂ250 mm), H/iPrOH¼1000:1, 0.3 mL minꢀ1
,
l
210 nm, tR(1S,2R)
*
(c 0.95, CHCl3), 72% ee; HPLC: Chiralcel AD-H (4.6ꢂ250 mm),
15.7 min, tR(1R,2R) 21.8 min, 70% ee; tR(1S,2S) 25.1 min, tR(1R,2S)
*
H/iPrOH¼200:1, 0.3 mL minꢀ1
,
l
210 nm, tR(þ) 43.3 min, tR(ꢀ)
39.7 min, 68% ee; 1H NMR (300 MHz, CDCl3)
d
1.12 (br d, 3J¼6.8 Hz,
46.1 min, 72% ee; 1H NMR (400 MHz, CDCl3)
d
0.81 (t, 3J¼7.5 Hz, 9H,
12H, H-9 (1S,2S)), 1.16 (br d, 3J¼6.8 Hz, 12H, H-9 (1S,2R)), 1.75 (ddt,
2J¼18.4 Hz, 3J¼3J¼6.2 Hz, 1H, HA-11 (1S,2R)), 1.88–2.06 (m, 3H, HB-
11 (1S,2R), HA-11, HB-11, (1S,2S)), 2.52–2.68 (m, 2H, H-12 (1S,2S) and
(1S,2R)), 2.72–2.99 (m, 4H, HA-10, HB-10 (1S,2S) and (1S,2R)), 3.67
(ps-s, 2H, H-8 (1S,2S)), 4.04 (ps-s, 2H, H-8 (1S,2R)), 4.98 (ddd,
2J¼1.7 Hz, 3J¼10.3 Hz, 4J¼1.0 Hz, 1H, Hcis-14 (1S,2R)), 5.01–5.08 (m,
2H, Htrans-14 (1S,2S) and (1S,2R)), 5.10 (ddd, 2J¼1.6 Hz, 3J¼11.4,
1.5 Hz, 1H, Hcis-14 (1S,2S)), 5.76 (ddd, 3J¼7.7, 17.3, 10.3 Hz, 1H, H-13
(1S,2R)), 5.86 (br d, 3J¼8.2 Hz, 1H, H-1 (1S,2R)), 5.83–5.92 (m, 1H, H-
13 (1S,2S)), 6.02–6.07 (m, 1H, H-1 (1S,2S)), 6.99–7.44 (m, 8H, H-ph
H3CCH2CH2CH2–), 1.10–1.39 (m, 18H, H3CCH2CH2CH2–), 1.18 (d,
3J¼6.4 Hz, 12H, (H3C)2CH–), 2.19 (ps-s, 1H, OH), 2.26–2.40 (m, 2H,
–CHAHBCHAHB–CH]CHCH2O–), 2.47–2.54 (m, 1H, –CHAHBCHAHB–
CH]CHCH2O–), 3.95 (sept, 3J¼6.4 Hz, 2H, (H3C)2CH–), 4.00 (dd,
3J¼7.7 Hz, 4J¼3.3 Hz, 2H, –CHAHBCHAHBCH]CHCH2O–), 5.63 (m,1H,
–CHAHBCHAHBCH]CHCH2O–), 5.67 (m, 1H, –CHAHBCHAHBCH]CH-
CH2O–), 6.00 (s, 1H, Hbenzylic), 6.99 (ddd, 3J¼3J¼7.3 Hz, 4J¼1.3 Hz, 1H,
H-5), 7.05 (dd, 3J¼7.8 Hz, 4J¼1.3 Hz,1H, H-3), 7.12 (ddd, 3J¼7.8, 7.3 Hz,
4J¼1.6 Hz, 1H, H-4), 7.20 (ps-d, 1H, H-6); 13C NMR (100 MHz, CDCl3)
d
10.1 (H3C–CH2CH2CH2–),13.3 (H3CCH2CH2CH2–), 20.8 ((H3C)2CH–),
(1S,2S) and (1S,2R)); 13C NMR (75 MHz, CDCl3)
d 20.5 (C-9 (1S,2R)),
27.2 (H3CCH2CH2CH2–), 28.5 (H3CCH2CH2–CH2–), 32.1 (–CHAHB
21.5 (C-9 (1S,2S)), 23.7 (C-10 (1S,2R)), 26.7 (C-10 (1S,2S)), 27.5 (C-11
(1S,2S)), 28.0 (C-11 (1S,2R)), 42.4 (C-12 (1S,2R)), 44.5 (C-12 (1S,2S)),
45.4 (C-8 (1S,2R)), 46.3 (C-8 (1S,2S)), 71.5 (C-1 (1S,2R)), 73.6 (C-1
(1S,2S)), 115.4 (C-14 (1S,2R)), 115.7 (C-14 (1S,2S)), 125.9(1), 129.9(4),
127.3, 127.8, 128.4, 128.5, 128.7, 129.9 (C-3 to C-6 (1S,2S) and
(1S,2R)), 135.5 (C-7 (1S,2R)), 135.7 (C-7 (1S,2S)), 136.8 (C-2 (1S,2R)),
136.9 (C-2 (1S,2S)), 138.8 (C-13 (1S,2R)), 139.2 (C-13 (1S,2S)), 155.2
(NC]O (1S,2R)), 155.6 (NC]O (1S,2S)); IR (ATR) 3076, 2997, 2969,
2933, 2873, 1683, 1643, 1492, 1476, 1432, 1368 cmꢀ1. HRMS (ESI)
calcd for C19H27NO2: m/z 324.1934 [MþNa]þ, found: m/z 324.1939
[MþNa]þ.
-
CHAHBCH]CHCH2O–), 33.0 (–CHAHBCHAHB–CH]CHCH2O–), 45.7
((H3C)2CH–), 63.1 (–CHAHB–CHAHBCH]CHCH2O–), 71.5 (Cbenzylic),
124.3 (C-5), 124.7 (C-6), 126.2 (C-4), 128.9 (C-3), 130.2 (–CHAHB-
–CHAHBCH]CHCH2O–), 131.2 (–CHAHBCHAHBCH]CHCH2O–), 134.6
(C-2), 141.5 (C-1), 155.4 (NC]O); IR (ATR) 3448, 3065, 2997, 2956,
2928, 2854, 1675, 1601, 1543, 1477, 1463, 1434, 1377, 1369 cmꢀ1; MS
(ESI)m/z632.3108[MþNa]þ. Anal.CalcdforC31H55NO3Sn:C, 61.19;H,
9.11; N, 2.30. Found: C, 61.42; H, 9.28; N, 2.19.
6.5.5. (ꢀ)-(S)-(E)-N,N-Diisopropylcarbamic acid [2-(5-bromo-
pent-3-enyl)-phenyl]-tributylstannyl-methyl ester (41)
According to the synthesis of allyl bromide 35, allyl alcohol 40
(122 mg, 0.20 mmol) was converted into allyl bromide derivative
41 using tetrabromomethane (83 mg, 0.25 mmol) and triphenyl-
phosphine (79 mg, 0.30 mmol). Flash chromatography on silica gel
8
N
9
O
O
3
6
1
2
7
12
*
4
5
13
14
(E/P¼1:15) afforded (ꢀ)-(S)-(E)-41 (130 mg, 97%) as colorless liquid,
11
E/Zꢃ98:2 (1H NMR). Rf 0.76 (E/P¼1:1); [
a
d
]
D
ꢀ3.9 (c 0.49, CHCl3),
20
10
72% ee; 1H NMR (400 MHz, CDCl3)
0.81 (t, 3J¼7.2 Hz, 9H,
H3CCH2CH2CH2–), 1.13–1.43 (m, 18H, H3CCH2CH2CH2–), 1.24 (d,
3J¼6.9 Hz, 12H, (H3C)2CH–), 2.23–2.43 (m, 2H, –CHAHBCHAHBCH]
CHCH2Br), 2.45–2.60 (m, 2H, –CHAHBCHAHBCH]CHCH2Br), 3.94
(dd, 3J¼7.5 Hz, 4J¼0.7 Hz, 2H, –CHAHBCHAHBCH]CHCH2Br), 3.97
(ps-s, 2H, (H3C)2CH–), 5.75 (tdt, 3J¼7.5, 15.3 Hz, 4J¼1.2 Hz, 1H,
–CHAHBCHAHBCH]CHCH2Br), 5.84 (s, 1H, Hbenzylic), 5.85 (dt,
3J¼15.3, 6.6 Hz, 1H, –CHAHB–CHAHBCH]CH–CH2Br), 7.03 (ddd, 3J¼
7.2, 7.0 Hz, 4J¼1.2 Hz, 1H, H-5), 7.07 (dd, 3J¼7.5 Hz, 4J¼1.2 Hz, 1H,
H-3), 7.16 (ddd, 3J¼7.5, 7.0 Hz, 4J¼1.7 Hz, 1H, H-4), 7.27 (ps-d,
Acknowledgements
This work was supported by the Deutsche For-
schungsgemeinschaft (SFB 424), the Fonds der Chemischen
Industrie, and the International NRW Graduate School of Chemis-
try, Mu¨nster, Germany (stipends for H.L.). Excellent experimental
support by Mrs. Cornelia Weitkamp is gratefully acknowledged.

H. Lange et al. / Tetrahedron 64 (2008) 9123–9135
9135
21. Trapping of intermediate palladium-species normally proceeds under inversion
of configuration, see Refs. 1 and 2.
Supplementary data
22. X-ray crystal structure analysis for (þ)-(S)-9: formula C21H24BrO3, M¼418.32,
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.tet.2008.06.092.
colorless crystal 0.30ꢂ0.06ꢂ0.03 mm, a¼5.772(1), b¼17.816(1), c¼19.288(1) Å,
V¼1983.5(4) Å3, rcalcd¼1.401 g cmꢀ3
,
m
¼29.82 cmꢀ1, empirical absorption cor-
rection (0.468ꢄTꢄ0.916), Z¼4, orthorhombic, space group P212121 (No. 19),
l
¼1.54178 Å, T¼223 K,
u
and
4
scans, 17,164 reflections collected (ꢅh, ꢅk, ꢅl),
]¼0.60 Åꢀ1, 3527 independent (Rint¼0.057) and 3293 observed re-
References and notes
[(sin
flections [Iꢄ2
q)/l
s
(I)], 239 refined parameters, R¼0.035, R2w¼0.081, Flack param-
eter 0.010(19), max. residual electron density 0.27 (ꢀ0.32) e Åꢀ3, hydrogen
atoms calculated and refined as riding atoms, CCDC 687366 contains the
supplementary crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre via http://
www.ccdc.cam.ac.uk/datarequest/cif.
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