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Diastereoselective Addition of Allylsilanes to Aldehydes Synthesis of Enantiomerically Pure Homoallylic Alcohols.

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[5] a) D. M. Heinekey, N. G. Payne, G. K. Schulte, J. Am. Chem. SOC.1988,
110, 2303; b) D. M. Heinekey, J. M. Millar, T. F. Koetzle, N. G. Payne,
K. W. Zilm, ibid. 1990, 112, 909; c) K. W. Zilm, D. M. Heinekey, J. M.
Millar, N. G. Payne, P. Demou, ibid. 1989, 111, 3088; d) K. W. Zilm,
D. M. Heinekey, J. M. Millar, N. G. Payne, S . P. Neshyba, J. C. Duchamp,
J. Szczyrba, ibid. 1990, 112, 920; e) K. W. Zilm, J. M. Millar, Adv. Magn.
Reson. 1990, I S , 163.
[6] a ) D . Jones, J. A. Lahinger, J. Weitekamp, J. Am. Chem. Soc. 1989, 111,
3087; b) C. R. Bowers, D. H. Jones, N. D. Kurnr, J. A. Labinger, M. G.
Pravica, D. P. Weitekamp, Adv. Magn. Reson. 1990, 15, 269.
[7] T. Arliguie, B. Chaudret, F. A. Jalon, A. Otero, J. A. Lopez, F. J. Lahoz,
OrganometaNics 1991, 10, 1888.
[8] J. C. Barthelat, B. Chaudret, J. P. Dauday, Ph. De Loth, R. Poilblanc, J.
Am. Chem. Soc. 1991, 113,9896.
[9] a ) P. M. Morse, E. C. G. Stuckelberg, Helv. Phys. Acta 1931, 4 , 337;
b) R. L. Somorjai, D. F. Hornig, 1 Phys. Chem. 1962,36,1980;c) J. Brickmann, H. Zimmermann, Ber. Bunsenges. Phys. Chem. 1966, 70, 157;
d) ibid. 1966, 70,521; e) ibid. 1967, 71,160; J. Chem. Phys. 1969,50,1608;
f ) J. Brickmann, H. Zimmermann, Z . Naturforsch 1968, 23 A , 11; g) J.
Laane, Appl Spectrosc. 1970, 24, 73.
[lo] a) D. Wallach, W A. Steele, J. Chem. Phys. 1976, 52, 2534; h) National
Bureau of Standards, Tables relating to Mathieu functions, Columbia
University Press, New York, 1951.
[ I l l J. Brickmann, Z . Naturforsch. 1973, 28A, 1759.
[12] L. Meschede, H. H. Limbach, J. Phys. Chem 1991, 95, 10267.
[I31 a) B. Wehrle, H. Zimmermann, H. H. Limbach, J. Am. Chem. Soc. 1988,
f10,7014; b) B. Wehrle, H. H. Limbach, Chem. Phys. 1988, f36, 223.
[14] J. D. McDonald, Annu. Rev. Phvs. Chem. 1979, 30, 29.
[I51 R. A. Harris, R. Silbey, J. Phys. Chem. 1983, 78, 7330.
1161 G. Binsch, J. Am. Chem. Soc. 1969, 91, 1304.
[I 71 The average value for J was calculated according to the following equation
1181:
J
=
compounds in enantiomerically pure form.[’’ Usually the
aldehydes are converted with chiral diols into cyclic acetals,
typically dioxolanes, dioxanes, dioxolanones, or dioxa41 Acyclic acetals have also been employed; however, poor selectivity was achieved. One negative aspect of
these methods is that the acetals are frequently formed as
mixtures of diastereomers which must then be purified.
Chiral homoallylic alcohols may also be prepared by the
reaction of aldehydes with chiral, nonracemic, allyl-metal
compounds often with very good
We describe here a method for the direct and simple preparation of homoallylic ethers with excellent de values (> 99 %)
from aliphatic aldehydes and trimethylsilyl ether derivatives
of chiral 3,2-aminoalcohols.
The best results were obtained with the trimethylsilyl ether
of (1 R,2R)-N-trifluoroacetylnorpseudoephedrine(2) (Scheme
l).”] Two equivalents of the aldehydes la-g were stirred at
Ph
2
1
OFCF,
3
v ,~ v3*, v,, = C(Ei - E’.){exp[- Ei/RT]
- e x p [ - E ’ , / R T ] ) / x { e x p [ - E ; / R T ]- exp[-E’./RT]}
EH3
where E:, i = 1,4 refers to the well known energy levels of the AX, AB, or
A, two-spin system in the nth environment, here the nth pair ofsplit states
as indicated in Figure 2. As long as J is much smaller than the Zeeman
energy one can show that this equation reduces to the simpler form [6]
J = C J.
4
exp[-E,IRT]/C exp[-E,/RTl
where En is the average energy of the nth pair of states. The energies were
calculated according to references 19, 101 assuming three pairs of split
states below the barrier.
[18] D. H. Jones, N. D. Kurur, D. P. Weitekamp, 33rd Experimental NMR
Conference Asilomar, Pacific Grove, USA, 1992, Book of Abstracts, p. 79
[19] We thank Dr. H. P. Trommsdorf (Grenoble) for pointingout the similarity
with the methyl group rotational tunnelingproblem. See for example E. 0.
Stejskal, H. S. Gutowsky, J. Chem. Phys. 1958, 28, 388; S. Clough, A.
Heidemann, J. Phys. C: Solid State Phys. 1979, 12, 761; J. Haupt, 2.
Naturforsch. 1971,26A, 1578; W. Miiller-Warmuth, R. Schiiler, M. Prager,
A. Kollmar, J. Magn. Reson. 1979,34, 83; H. Langen, A. S . Montjoie, W.
Muller-Warmuth, H. Stiller, Z. Naturforsch. 1987, 4 2 A , 1266.
1201 H. H. Limbach, Dynamic N M R Spec~roscopyin the Presence of Kinetic
Hydrogen Deuterium Isotope Effects, Chapter 2 in N M R Basic Principles
and Progress, Vof.26, Springer, Berlin, 1990.
Diastereoselective Addition of Allylsilanes
to Aldehydes: Synthesis of Enantiomerically Pure
Homoallylic Alcohols**
By Lutz E Tietze,* Angelika Dolle, and Kai Schiemann
Dedicated to Professor Theophil Eicher
on the occasion of his 60th birthday
Homoallylic alcohols are interesting synthetic building
blocks which can be prepared quite simply by the Lewis acid
induced addition of allylsilanes to aldehydes.[’] Numerous
procedures have been developed to allow access to these
5
Scheme 1. Synthesis of the homoallylic alcohols 5 (R groups see Table 1).
[a] CH,CI,, -78 “C. 0.1 equiv TMS-OTf. After 1h, addition of allyltrimethylsilane 3 and another 0.1 eqniv TMS-OTf. [b] THF, liquid NH,, -78’C,
2.5 equiv sodium. After I5min, addition of methanol.
- 78 “C with one equivalent of 2 in dichloromethane in the
presence of 0.1 equivalents of the trimethylsilyl trifluoromethanesulfonate (TMS-OTf) for one hour. The reaction
mixture was then treated with two equivalents of allyltrimethylsilane 3 and 0.1 equivalents of TMS-OTf at - 78 “C,
and allowed to stir for 48 hours at this temperature. After
aqueous workup and chromatography (silica gel, tert-butyl
methyl ether/petroleum ether) the homoallylic ethers 4a-g
were obtained in total yields of 49-81 YO(Table 1). Side
products in these reactions are the desilylated 2 (< 5 YO),
the
oxazolidine derivatives 7 (10-25 %), and the acetals 8
(< 5 YO).If aromatic aldehydes 1 h-k are employed, the
stereoselectivity is reduced (Table 1).
Application of other aminoalcohols as chiral inductors
resulted in considerably lower yields and stereoselectivities.
Reactions of aliphatic aldehydes with the trimethylsilyl ethers
of (1S,2R)-N-trifluoroacetylnorephedrine and (1S,2R)-N-trifluoroacetylephedrine provided products with respective de
values of 52-78, and 56-62Y0 and respective yields of 25-
[*] Prof. L. F. Tietze, Dr. A. Dolle, Dip].-Chem. K. Schiemann
[**I
Institut fur Organische Chemie der Universitat
Tammannstrasse 2, D-W-3400 Gottingen (FRG)
This research was supported by the Fonds der Chemischen Industrie
1372
0 VCH Verlagsgesellschaft mbH.
W-6940 Weinheim. 1992
OS70-0833~92/1010-1372
$3.50+ .25/0
Angew Chem. Int. Ed. Engl. 1992, 31, No. 10
Table 1. Conversions of l a - k . 2, and 3 to 4a-k and 5a-g
1,4,5 R
4: Yield
["/.I [a1
a
b
52(21)
73
81
65
71
55(31)
49(38)
61
73
89
80
C
d
e
f
g
h
i
i
k
de [%I [b]
[a]:"
[c]
+1.5
+9.6
-4.2
-6.6
-9.7
+38.5
-5.3
-133.5
-108.0
-101.2
-125.4
M.p.
["Cl [dl
5: Yield
["/.I
60.2
70.6
34.3
30.8
75.8
57.0
73.2
94.0
84.8
114.7
103.5
[g]
[g]
[gl
87
88
82
90
0
0
0
75
[a] Amount of recovered 2 in parentheses. [b] Determination by GC (Chromopack
WOCT CP SII 19CB, 0.22 mm x 50 m, H2).[c] Optical rotation of 4 (c = 1 in chloroform). [d] Melting point of4, recrystallized from tert-butyl methyl etheripetroleum
ether. [el The major product has ( R ) configuration. [fl The major product has (S)
configuration. [g] The alcohol in the crude reaction mixture was derivatized and
then detected.
63 and 32-34%. Even worse results were obtained with
aromatic aldehydes.
The homoallylic ethers 4 a-g could be converted by reductive cleavage with sodium in liquid ammonia['] into the homoallylic alcohols 5 a-g in good yields without racemization
(Table 1; THF, 2.5 equiv sodium, -78 "C, 15min). As an
additional product the enantiomerically pure amphetamine
6 was obtained which can easily be removed by distillation
or chromatography (silica gel, tert-butyl methyl ether/
petroleum ether). The homoallylic ether 4 k prepared from
p-methoxybenzaldehyde may also be cleaved selectively to
5 k and 6 ; the reductive cleavage of the homoallylic
ethers 4 h-j obtained from aromatic aldehydes 1 i j and cinnamaldehyde did not proceed as desired.
For the determination of the absolute configuration of 5,
an 87: 13 mixture of the enantiomers of ent-5b and 5 b was
+ )-a-methoxy-a-trifluoromethyl-phenylesterified with (R)-(
acetyl chloride, and examined by spectroscopy. The absolute
configuration of the homoallylic alcohols could be deduced
following Mosher's rules"I from the positions of the signals
for 2-H, and 4-H, of the ester of 5 b (6 = 1.61, 2.41), and for
2-H, and 4-H, of the ester o f ent-5b (6 = 1.69, 2.35). The
assignment was confirmed by comparison of the optical rotation of (R)-dodec-l-en-4-01 (5d) ([alDZ0= +10.5, c =
0.65 in CCI,) with the literature value ( [ ~ r ] , ~ ~ = + 10.2, c =
3.5 in CC1,).r41
The high stereoselectivity of the reaction is probably due
to the selective formation of the oxazolidinium ion 9, which
is subsequently opened in an SN2-typereaction. This hypothesis is also supported by the appearance of side product 7;
interestingly, treatment of 7 with 3 in the presence of Bronsted
or Lewis acids does not lead to 4. The low selectivity achieved
CAS Registry numbers:
1a,75-07-0;1b,123-38-6; 1c,111-71-7; Id, 124-19-6; le,96-17-3;lf,630-19-3;
l g , 2043-61-0; l h , 104-55-2; li, 100-52-7; l j , 3132-99-8; l k , 123-11-5; 2,
143143-10-6; 3,762-72-1; 4a, 143143-11-7; 4b, 143143-12-8; 4c, 143143-13-9;
4d, 143143-14-0; 4e, 143143-15-1; 4f, 143143-16-2; 4g, 143143-17-3; 4h (isomer I), 143143-18-4;4h (isomer 2), 143234-59-7; 44 (isomer 1) 143143-19-5;4i
(isomer 2), 143234-60-0; 4 j (isomer l), 143143-20-8; 4 j (isomer 21, 14323461-1; 4k, 143143-21-9; 5a, 64584-92-5; 5b, 51795-28-9; 5 c , 143143-22-0; Sd,
85029-09-0; Se, 143143-23-1; 51,67760-86-5;5g, 94340-22-4; Sk, 115413-90-6;
(IR,2R)-norpseudoephedrine hydrochloride, 53643-20-2; methyl trifluoroacetate, 431-47-0.
[I] Reviews: J. S. Panek in Comprehensive Organic Synthesis, Vol. 1 (Eds.:
B. M. Trost, I. Fleming), Pergamon, Oxford, 1991, pp. 579-627, I. Fleming, Org. React. N . Z 1989, 37, 57; G. Majetich, Org. Synth. Theory Appl.
1989, 1, 173, Organosilicon and Bioorganosilicon chemistrj~:Structure,
Bonding, Reactivity and Synthetic Application (Ed.: H. Sakurai), Halsted,
New York, 1985.
[2] Reviews: D. Seebach, R. Imwinkelried, T. Weber, Mod. Synth. Methods
1986, 4, 125-259; D. Schinzer, Janssen Chim. Acta 1988, 6, 11: H. J. Altenbach, Nachr. Chem. Tech. Lab. 1988, 36, 1212-1217.
[3] D. Seebach, R. Imwinkelried, G. Stucky, Helv. Chim. Acta 1987, 70, 448464; S. E. Denmark, N. G. Almstead, J. Am. Chem. Soc. 1991,113, 80898110; W S. Johnson, J. D. Elliot, ibid. 1983,105,2088-2089; J. M. McNamara, Y. Kish, ibid. 1982, 104, 7371-7374; H. G. Howell, P. R.
I
Org. Chem. 1985, 50,2598-2600; S. F. Martin,
Brodfuehrer, C. Sapino, .
C. Gluchowsky, C. L. Campbell, R. C . Chapman, ibid. 1984, 49, 25132516.
[4] D. Seebach, R. Imwinkelried, G. Stucky, Angew. Chem. 1986,98,182-183;
Angew. Chem. Int. Ed. Engl. 1986, 25, 178.
[5] I. E. Mark& A. Mekhalfia, Tetrahedron Lett. 1991, 32, 4779-4782; S. E.
Denmark. T. M. Wilson, J. Am. Chem. Soc. 1989, 111, 3475-3476; D.
Seebach, R. Imwinkelried, Angew. Chem. 1985,97,781-782; Angew. Chem.
Int. Ed. Engl. 1985, 24, 765.
161 R. W. Hoffniann, G. Niel, A. SchIapbach, Pure Appf.Chem. 1990,62,19931998; H. C. Brown, R. S. Randad, K. S. Bhat, M. Zaidlewicz, U. S.
Racherla, J. Am. Chem. Soc. 1990, ff2, 2389-2392; R. 0. Duthaler, M.
Riediker, Angew. Chem. 1989, 101, 488-490; Angew. Chem. Int. Ed. Engl.
1989,28,494;E. J. Corey, C. M. Yu,S. S. Kim, L Am. Chem. Soc. 1989,111,
5495-5496; M. M. Midland, S. C. Preston, ibid. 1982, 104,2330-2331.
[7] The hydrochloride of (IR,2R)-norpseudoephedrine was dissolved in methanol and treated with 1.1 equiv triethylamine. After the addition of
1.2 equiv methyl trifluoroacetate (0 "C), the reaction mixture was stirred for
15h at room temperature. The solvent was removed completely under vacuum and the residue dissolved in dichloromethane.This solution was cooled
to O T , treated with 2.5 equiv trietbylamine and 1.2 equiv chlorotrimethylsilane, and stirred for 15 h a t room temperature. After aqueous workup the
trifluoroacetylated silyl ether was purified by distillation [B.p. 78 "C
(0.01 mbar); [aIDzo= f16.0 (c = 1 in methanol)].
[S] M. Hudlicky, Reduction in Organic Chemislry. Wiley, New York, 1984,
p. 82.
[9] H. A. Mosher, J. A. Dale, J. Am. Chem. Soc. 1973, 95, 512-519; H. A.
Mosher, J. A. Dale, D. L. Dull, J Org. Chem. 1969, 31, 2543-2549.
5'-P-Borane-Substituted Thymidine Monophosphate
and Triphosphate**
By Jeno Tomasz,* Barbara Ramsay Shaw,* Ken Porter,
Bernard E: Spielvogel,* and Anup Sood*
We describe here the synthesis and some properties of
5'-P-borane-substituted thymidine phosphate 5 and triphosphate 6 (boranophosphates, -triphosphates), the first nucleoside 5'-boranophosphates and -triphosphates, respecNu
9
10
when aromatic aldehydes are employed may be explained by
the existence of the acyclic oxonium ion 10. The possible
mesomerism when R is a phenyl group should make this intermediate lower in energy than when R is a alkyl group.
Received: April 11, 1992 [25301IE]
German version: Angew. Chem. 1992, 104, 1366
Angew. C h e m Int. Ed. Engl. 1992, 31, No. 10
0 VCH
['I Dr. J. Tomasz, Dr. B. R. Shaw, Dr. K. Porter
Chemistry Department, Duke University
Durham, NC 27706 (USA)
Dr. B. E Spielvogel, Dr. A. Sood
Boron Biologicals, 533 Pylon Drive
Raleigh, NC 27606 (USA)
[**I Boron-Containing Nucleic Acids, Part 3. This research was supported by
the U.S. National Institute of Health (1 R43 A1 30887-01) and the
American Cancer Society (NP 741). The HPLC study by F. Huang is
gratefully acknowledged. - Part 2: [2].
Verlagsgeseifschaft mbH, W-6940 Wernheim. 1992
0570-0833~92j1010-1373
$3.50+ ,2510
1373
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aldehyde, diastereoselective, synthesis, enantiomerically, allylsilanes, additional, homoallylic, alcohol, pure
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