Formation of chiral β-silyl-vinyl ethers

Article abstract of DOI:10.1080/10426500307948

Chiral formates derived from propane-1,2-diol, 1,2-O-isopropylidene-α-D-xylo- and α-D-gluco-furanoses were subjected to treatment with cyelopentadienyl [tris(trimethylsilytmethyl)] titanium (IV). A mixture of the corresponding (E)- and (Z)-β-silylvinyl et

Full text of DOI:10.1080/10426500307948

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Phosphorus, Sulfur, and Silicon and the Related
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Formation of Chiral β-Silyl-Vinyl Ethers
Robert Łysek a , Ewa Woźny a & Marek Chmielewski a
a Institute of Organic Chemistry , Polish Academy of Sciences , Kasprzaka, Warsaw, Poland
Published online: 27 Oct 2010.
To cite this article: Robert Łysek , Ewa Woźny & Marek Chmielewski (2003) Formation of Chiral β-Silyl-Vinyl Ethers,
Phosphorus, Sulfur, and Silicon and the Related Elements, 178:2, 327-340, DOI: 10.1080/10426500307948
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Phosphorus, Sulfur and Silicon, 2003, Vol. 178:327–340
C
Copyright 2003 Taylor & Francis
1042-6507/03 $12.00 + .00
DOI: 10.1080/10426500390170453
FORMATION OF CHIRAL -SILYL-VINYL ETHERS
Robert Lysek, Ewa Woz´ny, and Marek Chmielewski
Institute of Organic Chemistry of the Polish Academy
of Sciences, Kasprzaka, Warsaw, Poland
(Received May 28, 2002)
Chiral formates derived from propane-1,2-diol, 1,2-O-isopropylidene-
-D-xylo- and -D-gluco-furanoses were subjected to treatment with
cyclopentadienyl [tris(trimethylsilylmethyl)] titanium (IV). A mixture
of the corresponding ( E)- and ( Z)- -silylvinyl ethers were obtained with
predominance of the former. It was found that in contrast to ( Z)-vinyl
ethers, which give -lactams with chlorosulfonyl isocyanate, the ( E)-
vinyl ethers gave unstable cycloadducts which undergo rapid elimina-
tion reaction leading to ( E)- , -unsaturated amides.
Keywords: [2+2]cycloaddition; -lactams; vinyl silanes
INTRODUCTION
Introduction of a silyl substituent to the vinyl ether group should
open an access to a variety of silylated cyclic compounds via cyclo-
addition reactions. A few years ago, we reported that asymmetric
[2 + 2]cycloaddition of chlorosulfonyl isocyanate to (Z) 1,2-O-
isopropylidene-3-O-(20-silylvinyl)-5-O-trityl- -D-xylofuranoses
pro-
ceeded in a high yield and with excellent stereoselectivity to give ex-
clusively the corresponding cis-azetidin-2-ones with (R)-configuration
at the C-4 carbon atom.1 Although 3-silylated azetidin-2-ones display
tendency to facile desilylation under basic conditions, and therefore
their use for the -lactam synthesis is limited, C-silyl vinyl ethers
could be attractive substrates for organic synthesis.1,2
This research was supported by the Polish State Committee for Scientific Research
(KBN), grant no. T 09/PBZ.6.04. The authors thank Dr. B. Furman for valuable discus-
sions. R. L. thanks the Foundation for Polish Science for the FNP 2001 scholarship.
Address correspondence to Marek Chmielewski, Institute of Organic Chemistry,
Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. E-mail:
chmiel@icho.edu.pl
327

328
R. Lysek et al.
(Z) Silyl vinyl ethers can be obtained by a sequence of reactions in-
volving formation of alkoxyacetylene, introduction of a silyl substituent
to the terminal carbon atom, and hydrogenation of the triple bond over
Lindlar’s catalyst.3 Attempts to obtain (E)-configuration of the double
bond via reduction using complex hydrides or sodium in liquid ammo-
nia failed.1,3 The only successful attempt to synthesize the (E) -silyl
vinyl ether has been reported by Denmark and Thorarensen.3 The au-
thors used addition of lithiodimethylphenylsilane to the triple bond of
alkoxyacetylene in the presence of cyanocuprate.
RESULTS AND DISCUSSION
The search for facile and effective preparation of chiral (E)
-
silyl-vinyl ethers prompted us to investigate the cyclopentadienyl
[tris(trimethylsilylmethyl)] titanium (IV) (1), Petasis’ reagent,4 for the
conversion of carbonyls to alkenyl silanes. We selected as substrates
formate 3 derived from compound 2, 3-O- and 5-O-formates 6, 7, 13–17
obtained from corresponding 1,2-O-isopropylidene- -D-xylo- 4,5 56 and
-D-glucofuranoses 8,7 9,8 10,9 11,8 and 12,10 respectively. It should be
noted that so far a variety of aliphatic and aromatic aldehydes and ke-
tones, lactones and methyl benzoate have been used as substrates for
Petasis’ reagent,4 however, to the best of our knowledge, reactions of
formates have not been reported yet.
CHART 1

Formation of Chiral -Silyl-Vinyl Ethers
329
Reactions of formates 3, 6, 7, 13–17 with easy to handle Petasis’
reagent 14 were performed under standard conditions. In all cases un-
separable mixtures of (E) and (Z) -silyl-vinyl ethers 18/19, 20/21,
22/23, 24/25, 26/27, 28/29, 30/31, and 32/33 were obtained in good
yield. The observed values of ratio of geometric isomers produced in
these reactions are shown in Scheme 1. In the case of 5-O-substituted
compounds, one can rationalize results as a function of the size of sub-
stituents at O-3 and O-5 oxygen atoms. Bulky substituents at both
SCHEME 1

330
R. Lysek et al.
oxygen atoms promote formation of (E)-stereoisomers; compare Tr,
TIBS and Ts at O-6, and Bn versus Me at O-3 atom (Scheme 1). This
phenomenon can be explained in terms of smaller steric requirements
of (E)-olefins versus respective (Z)-isomers.
Reactivity of (E) -silyl-vinyl ethers in comparison to the correspond-
ing (Z)-isomers was investigated using [2+2]cycloaddition reaction with
chlorosulfonyl isocyanate (CSI). In contrast to (Z) olefins, which react
readily to provide the corresponding -lactams,1 (E)-olefins either do
not form any -lactam or it is obtained only in minute amounts. Trans
substituted cycloadduct, which is probably formed from (E)-olefin and
CSI, undergoes rapid opening of the four-membered ring to yield (E)
, -unsaturated amide which subsequently is subjected to hydrogena-
tion by Red-Al or to further decomposition. The presence of trans , -
unsaturated amides was detected in substantial amounts in a crude
postreaction mixtures by NMR spectra. It should be pointed out, how-
ever, that we did not notice any signals corresponding to the respective
cis-isomer. For example, the mixture 20/21 in reaction with CSI gave cis-
cycloadducts 34 in 15% yield accompanied by traces of trans-compound
35 which was isolated by HPLC and fully characterized. Examination
of the crude postreaction mixture by 1H NMR revealed the presence of
two doublets at 7.62 and 5.36 with J = 11.8 Hz which were assigned
to the , -unsaturated amide 36. Similarly, in the case of the mixture
CHART 2

Formation of Chiral -Silyl-Vinyl Ethers
331
28/29 examination of the postreaction mixture showed the presence of
two cis-azetidin-2-ones 37 [ : 5.41 (d, 1H, J = 4.4 Hz, H-40)] and 38 [ :
5.18 (d, 1H, J = 4.4 Hz, H-40)] and the unsaturated amide 39 [ : 7.80 and
5.31 (2d, 2H, J = 11.9 Hz, H-10 and H-20)] in a ratio of about 1:0.16:1.5
respectively. We did not notice any signal that could be assigned to the
trans-substituted -lactam. In neither case did we find any signal that
could be assigned to the (Z) , -unsaturated amide 40 and 41.
It is not clear why only the trans 3,4-substituted cycloadducts un-
dergo elimination reaction. The mechanism for the ring opening and
elimination of the silyl substituent in the trans substituted cycloadducts
follows probably the Peterson-like reaction shown in Scheme 2. This
can be explained in terms of a bend conformation of the four-membered
-lactam ring, which in the case of trans-cycloadduct adopts a geom-
etry suitable for the elimination (Scheme 2a). Heterolytic cleavage of
the C N bond is accelerated by the stabilization of the negative charge
at the nitrogen atom by carbonyl and sulfonyl groups. Corresponding
cis-cycloadduct does not adjust to such arrangement (Scheme 2b). It
indicates that the alkoxy substituent prefers a quasi-equatorial posi-
tion, otherwise both cis- and trans-adducts should undergo the same
elimination leading to the (Z)- and (E)-olefin respectively. Any other
explanation of the reported phenomenon, based on the two-step mech-
anism of cycloaddition involving formation of the zwitterions 42 does
not explain the different reactivity of (Z)- and (E)-alkoxyvinylsilanes.
SCHEME 2
(Z)-Vinylsilanes have been reported to react more rapidly than re-
spective (E)-isomers.11 Stereospecificity of reaction of (Z)- and (E)-
vinylsilanes have also been reported,12 we did not notice, however, any
information concerning the different reactivity of (Z)- and (E)-isomers
with electrophiles.12a

332
R. Lysek et al.
CONCLUSION
It was demonstrated that sugar formates readily react with Peta-
sis’ reagent to provide mixtures of the corresponding (E)- and (Z)-
alkoxyvinylsilanes with predominance of the former isomer. The ratio
of geometric isomers depends on the size of neighboring substituents.
More bulky substituents promote larger content of (E)-isomers. It was
shown that in contrast to the (Z)-isomers (which with CSI produce cis
-lactams1), the (E)-isomers yield unstable adducts which undergo
rapid opening of the four-membered ring with elimination of the silyl
substituent to give (E)- , -unsaturated alkoxyamides.
Experimental
M.p.’s were determined on a Kofler hot-stage apparatus with a micro-
1
scope and are uncorrected. H NMR spectra were obtained on Bruker
Avance 500 and Varian Gemini AC-200 spectrometers for solution in
CDCl3 with tetramethylsilane as an internal standard and are ex-
pressed as values. Signals for aromatic protons (phenyls) were not
characteristic and therefore were not included in the reported spec-
tral data. IR spectra were recorded on a Perkin Elmer FT-IR Spec-
trum 2000 spectrophotometer. Mass spectra were determined with an
AMD 604 Inectra GmbH spectrometer and HPLC-MS system with
Mariner and API 356 detectors. Optical rotation were measured using
a JASCO P 3010 polarimeter at ambient temperature. The progress
of all reactions was checked using thin-layer chromatography (TLC)
on Merck silica gel 60-F254 plates. Column flash chromatography was
performed with Merck silica gel 60 (230–400 mesh). Cyclopentadienyl
[tris(trimethylsilylmethyl)] titanium(IV) (1), the Petasis’ reagent, was
obtained according to literature procedure.4 Compounds 2, 4,5 5,6 8,7
9,8 10,9 11,8 and 1210 were synthesized according to the previously re-
ported procedures.
(2S)-1-O-(2,4,6-Triisopropylbenzenesulfonyl)-
propane-1,2-diol (2)
Compound 2 was obtained from methyl (S)-lactate using a four-
step procedure involving formation of acetal, reduction of the methoxy-
carbonyl function,13 protection of the primary hydroxymethyl group
with 2,4,6-triisopropylbenzenesulfonyl chloride and deprotection of the
22
secondary hydroxy group. M.p. 66–68 C. [ ]D +5.8 (C 1, CH2Cl2).
1
1
IR: 3600 cm (CH2Cl2). H NMR (500 MHz, CDCl3): 1.20 (d, 3H,
J = 6.5 Hz, CH3), 1.27 (m, 18H, 3
CHMe2), 2.10 (br s, 1H, OH),

Formation of Chiral -Silyl-Vinyl Ethers
333
2.91 (sept., 1H, J = 6.9 Hz, p-CHMe2), 3.91 (dd, 1H, J = 7.4 Hz, J = 10.2
Hz, H-1a), 4.03 (dd, 1H, J = 3.2 Hz, J = 10.2 Hz, H-1b), 4.07–4.16 (m, 3H,
H-2, 2 o-CHMe2), 7.19 (s, 1H, CHO). 13C NMR (125 MHz, CDCl3):
18.67, 23.51, 24.70, 29.67, 34.26, 65.87, 73.87, 123.85, 129.15, 150.87,
153.94. MS (LSIMS, HR) m/z: [M + H]+ calcd for C18H31O4S: 343.19431.
Found: 343.19502.
Anal. Calcd for C18H30O4S (342.51): C, 63.12; H, 8.83. Found: C,
62.92; H, 8.73.
(2S)-2-O-Formyl-1-O-(2,4,6-triisopropylbenzenesulfonyl)-
propane-1,2-diol (3). General Procedure
Compound 2 (1.2 g, 3.5 mmol) was dissolved in dry pyridine (7 mL),
the solution was cooled to 0 C and a 1:1 mixture of Ac2O HCO2H
(FAM)14 (7 mL) was added dropwise during 5 min. Stirring was con-
tinued for 3 h (TLC monitoring) while warming up to room tempera-
ture. Subsequently, the mixture was poured into a cold saturated aque-
ous NaCl solution and extracted with toluene (3 30 mL). The extract
was washed with water, dried (MgSO4), filtered, and concentrated. The
crude product was purified by column chromatography on silica gel us-
ing hexane-ethyl acetate 8.5:1.5 v/v as an eluent to give 3 (1.2 g, 92%).
22
1
M.p. 85–86 C. [ ]D
17.7 (C 1, CH2Cl2). IR: 1727 cm (CH2Cl2).
1H NMR (500 MHz, CDCl3): 1.26 (d, 18H, J = 6.9 Hz, 3
CHMe2), 1.33
(d, 3H, J = 6.5 Hz, CH3), 2.90 (sept., 1H, J = 6.9 Hz, p-CHMe2), 4.08–
4.15 (m, 4H, H-1a, H-1b, 2 o-CHMe2), 5.20–5.27 (m, 1H, H-2), 7.92 (s,
1H, CHO). MS (LSIMS, HR) m/z: [M + Na]+ calcd for C19H30O5SNa:
393.17117. Found: 393.17140.
Anal. Calcd for C19H30O5S (370.52): C, 61.64; H, 8.16. Found: C,
61.65; H, 7.98.
3-O-Formyl-1,2-O-isopropylidene-5-O-trityl-
-D-xylofuranose (6)
Compound 6 was obtained from 4 according to the procedure de-
22
scribed above (74%). Solid foam. [ ]D
41.3 (C 1, CH2Cl2). IR:
1731 cm (film). 1H NMR (200 MHz, CDCl3): 1.30, 1.54 (2s, 6H,
1
2
CH3), 3.20 (dd, 1H, J = 9.2 Hz, J = 7.4 Hz, H-5a), 3.46 (dd, 1H,
J = 9.2 Hz, J = 5.5 Hz, H-5b), 4.41–4.50 (m, 1H, H-4), 4.43 (d, 1H, J =
3.8 Hz, H-2), 5.40 (d, 1H, J = 3.0 Hz, H-3), 5.86 (d, 1H, J = 3.8 Hz, H-1),
7.77 (s, 1H, CHO). MS (EI, HR) m/z: M+ calcd for C28H28O6: 460.18860.
Found: 460.18887.
Anal. Calcd for C28H28O6 (460.54): C, 73.03; H, 6.13. Found: C, 72.93;
H, 6.09.

334
R. Lysek et al.
3-O-Formyl-1,2-O-isopropylidene-5-O-tosyl-
-D-xylofuranose (7)
Compound 7 was obtained from 5 according to the procedure de-
22
1
scribed above (77%). Oil. [ ]D
12.4 (C 1.6, CH2Cl2). IR: 1731 cm
(film). 1H NMR (400 MHz, CDCl3): 1.30, 1.48 (2s, 6H, 2 CH3), 2.46
(s, 3H, tosyl), 4.19 (d, 2H, J = 6.4 Hz, H-5a, H-5b), 4.45–4.50 (m, 1H,
H-4), 4.50 (d, 1H, J = 3.7 Hz, H-2), 5.30 (d, 1H, J = 2.9 Hz, H-3), 5.87 (d,
1H, J = 3.7 Hz, H-1), 7.92 (m, 1H, CHO). 13C NMR (125 MHz, CDCl3):
21.65, 26.19, 26.61, 65.67, 75.23, 75.84, 82.99, 104.83, 112.71, 128.05,
129.93, 132.44, 145.18, 159.12. MS (EI, HR) m/z: [M-CH3]+ calcd for
C15H17O8S: 357.06441. Found: 357.06498.
Anal. Calcd for C16H20O8S (372.4): C, 52.31; H, 5.85. Found: C, 52.15;
H, 5.83.
5-O-Formyl-1,2-O-isopropylidene-3-O-methyl-6-O-trityl-
-D-glucofuranose (13)
Compound 13 was obtained from 8 according to the procedure de-
22
scribed above (77%). White solid. M.p. 127–129 C. [ ]D
35.4 (C 0.57,
1
1
CH2Cl2). IR: 1730 cm (CHCl3). H NMR (500 MHz, CDCl3): 1.31,
1.49 (2s, 6H, 2 CH3), 3.33 (s, 3H, OMe), 3.39 (dd, 1H, J = 10.6 Hz,
J = 6.2 Hz, H-6a), 3.47 (dd, 1H, J = 10.6 Hz, J = 2.2 Hz, H-6b), 3.72
(d, 1H, J = 3.2 Hz, H-3), 4.45 (dd, 1H, J = 8.9 Hz, J = 3.2 Hz, H-4), 4.54
(d, 1H, J = 3.7 Hz, H-2), 5.23–5.28 (m, 1H, H-5), 5.83 (d, 1H, J = 3.7 Hz,
H-1), 8.09 (s, 1H, CHO). 13C NMR (125 MHz, CDCl3): 26.28, 26.77,
57.74, 63.04, 70.82, 77.62, 81.13, 83.42, 86.68, 105.33, 111.90, 126.98,
127.77, 128.72, 143.77, 160.77. MS (EI, HR) m/z: M+ calcd for C30H32O7:
504.21480. Found: 504.21795.
Anal. Calcd for C30H32O7 (504.59): C, 71.41; H, 6.39. Found: C, 71.36;
H, 6.54.
5-O-Formyl-1,2-O-isopropylidene-3-O-methyl-6-O-
(2,4,6-triisopropylbenzenesulfonyl)- -D-glucofuranose (14)
Compound 14 was obtained from 9 according to the procedure de-
22
scribed for compound 3 (88%). White solid. M.p. 77–79 C. [ ]D
17.2
1
1
(C 0.8, CH2Cl2). IR: 1733 cm (CH2Cl2). H NMR (500 MHz, CDCl3):
1.25 (d, 18H, J = 6.9 Hz, 3 CHMe2), 1.30, 1.45 (2s, 6H, 2 CH3),
2.90 (sept., 1H, J = 6.9 Hz, p-CHMe2), 3.33 (s, 3H, OMe), 3.74 (d, 1H,
J = 3.3 Hz, H-3), 4.05–4.15 (m, 2H, o-CHMe2), 4.26 (dd, 1H, J = 11.4 Hz,
J = 6.2 Hz, H-6a), 4.33 (dd, 1H, J = 7.3 Hz, J = 3.3 Hz, H-4), 4.48
(dd, 1H, J = 11.4 Hz, J = 2.1 Hz, H-6b), 4.54 (d, 1H, J = 3.7 Hz, H-2), 5.35
(m, 1H, H-5), 5.83 (d, 1H, J = 3.7 Hz, H-1), 7.98 (s, 1H, CHO). 13C NMR
(125 MHz, CDCl3): 23.51, 24.71, 26.22, 26.80, 29.62, 34.24, 57.83,

Formation of Chiral -Silyl-Vinyl Ethers
335
67.75, 68.79, 77.99, 81.08, 83.41, 105.30, 112.18, 123.74, 129.45, 150.86,
153.72, 159.54. MS (EI, HR) m/z: M+ calcd for C26H40O9S: 528.23931.
Found: 528.23657.
Anal. Calcd for C26H40O9S (528.68): C, 59.07; H, 7.63. Found: C,
59.32; H, 7.92.
5-O-Formyl-1,2-O-isopropylidene-3-O-methyl-
6-O-tosyl- -D-glucofuranose (15)
Compound 15 was obtained from 10 according to the procedure de-
22
scribed for compound 3 (84%). Oil. [ ]D
21.1 (C 1.17, CH2Cl2). IR:
1732 cm (film). 1H NMR (200 MHz, CDCl3): 1.31, 1.47 (2s, 6H, 2
CH3), 2.45 (s, 3H, tosyl), 3.34 (s, 3H, OMe), 3.72 (d, 1H, J = 3.4 Hz,
H-3), 4.21 (ddd, 1H, J = 11.3 Hz, J = 5.7 Hz, J = 0.6 Hz, H-6a), 4.31
(dd, 1H, J = 7.7 Hz, J = 3.4 Hz, H-4), 4.44 (dd, 1H, J = 11.3 Hz,
J = 2.2 Hz, H-6b), 4.54 (d, 1H, J = 3.6 Hz, H-2), 5.29 (dddd, J = 7.7 Hz,
J = 5.7 Hz, J = 2.2 Hz, J = 0.6 Hz, 1H, H-5), 5.81 (d, 1H, J = 3.6 Hz,
H-1), 7.95 (s, 1H, CHO). MS (LSIMS, HR) m/z: [M + H]+ calcd for
C18H25O9S: 417.12193. Found: 417.11920.
1
Anal. Calcd for C18H24O9S (416.46): C, 51.91; H, 5.80. Found: C,
52.11; H, 6.02.
3-O-Benzyl-5-O-formyl-1,2-O-isopropylidene-6-O-(2,4,6-
triisopropylbenzenesulfonyl)- -D-glucofuranose (16)
Compound 16 was obtained from 9 according to the procedure de-
22
scribed for compound 3 (93%). Oil. [ ]D
37.7 (C 1.35, CH2Cl2). IR:
1732 cm (film). 1H NMR (500 MHz, CDCl3): 1.24 (m, 18H, 3
1
CHMe2), 1.30, 1.45 (2s, 6H, 2
CH3), 2.89 (sept, 1H, J = 6.9 Hz, p-
CHMe2), 3.98 (d, 1H, J = 3.3 Hz, H-3), 4.11 (m, 2H, o-CHMe2), 4.27 (dd,
1H, J = 11.4 Hz, J = 5.4 Hz, H-6a), 4.36 (dd, 1H, J = 7.9 Hz, J = 3.3 Hz,
H-4), 4.45, 4.60 (2d, 2H, J = 11.6 Hz, benzyl), 4.53 (dd, 1H, J = 11.4 Hz,
J = 2.2 Hz, H-6b), 4.57 (d, 1H, J = 3.7 Hz, H-2), 5.35 (m, 1H, H-5), 5.86
(d, 1H, J = 3.7 Hz, H-1), 7.78 (s, 1H, CHO). 13C NMR (125 MHz, CDCl3):
23.51, 24.71, 24.72, 26.27, 26.81, 29.62, 34.23, 67.49, 68.56, 72.15,
77.60, 80.72, 81.68, 105.28, 112.23, 123.73, 128.21, 128.23, 128.56,
129.53, 136.64, 150.82, 153.70, 159.47. MS (LSIMS, HR) m/z: [M + Na]+
calcd for C32H44O9SNa: 627.26037. Found: 627.26059.
3-O-Benzyl-5-O-formyl-1,2-O-isopropylidene-
6-O-tosyl- -D-glucofuranose (17)
Compound 17 was obtained from 12 according to the general proce-
22
dure described earlier (94%). Colorless crystals. M.p. 98–100 C. [ ]D
36.8 (C 0.47, CH2Cl2). IR: 1732 cm (film). 1H NMR (200 MHz,
1

336
R. Lysek et al.
CDCl3): 1.31, 1.47 (2s, 6H, 2
CH3), 2.43 (s, 3H, tosyl), 3.96 (d,
1H, J = 3.3 Hz, H-3), 4.21 (dd, 1H, J = 11.4 Hz, J = 5.2 Hz, H-6a), 4.33
(dd, 1H, J = 8.0 Hz, J = 3.3 Hz, H-4), 4.42, 4.59 (2d, 2H, J = 11.6 Hz, ben-
zyl), 4.46 (dd, 1H, J = 11.4 Hz, J = 2.2 Hz, H-6b), 4.57 (d, 1H, J = 3.7 Hz,
H-2), 5.30–5.32 (m, 1H, H-5), 5.83 (d, 1H, J = 3.7 Hz, H-1), 7.95
(s, 1H, CHO). 13C NMR (125 MHz, CDCl3): 21.61, 26.28, 26.85, 68.21,
68.41, 72.14, 77.34, 80.63, 81.66, 105.23, 112.28, 128.01, 128.21, 128.26,
128.57, 129.80, 132.80, 136.61, 144.82, 159.41. MS (LSIMS, HR) m/z:
[M + Na]+ calcd for C24H28O9SNa: 515.13517. Found: 515.13575.
(E) and (Z) (2S)-2-O-(20-Trimethylsilyl-vinyl)-1-O-(2,4,6-
triisopropylbenzenesulfonyl)propane-1,2-diol (18/19)
General procedure. A solution of formate 3 (0.6 g, 1.6 mmol) and tita-
nium complex 1 (0.72 g, 1.9 mmol) in toluene (10 mL) was stirred under
reflux (110 C). After 3 h (TLC), the solvent was removed and the residue
was purified by column chromatography on silica gel using hexane-
ethyl acetate (97:3, v/v) as an eluent to give a mixture of compounds 18
and 19, in a ratio ca. 1.7:1 (0.3 g, 42%) as an oil. IR: 1605 cm 1 (CH2Cl2).
Compound 18: 1H NMR (500 MHz, CDCl3) selective signals taken from
the spectrum of the mixture: 4.55 (d, 1H, J = 14.8 Hz, CH ), 6.16 (d,
1
1H, J = 14.8 Hz, OCH ). Compound 19: H NMR (500 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 4.23 (d, 1H,
J = 8.3 Hz, CHSi ), 6.52 (d, 1H, J = 8.3 Hz, OCH ). MS (LSIMS, HR)
m/z: [M + H]+ calcd for C23H41O4SiS: 441.24949. Found: 441.25094.
Anal. Calcd for C23H41O4SiS (440.73): C, 62.68; H, 9.15. Found: C,
62.84; H, 9.26.
(E) and (Z) 1,2-O-Isopropylidene-3-O-(20-trimethylsilyl-
vinyl)-5-O-trityl- -D-xylofuranose (20/21)
General procedure. A mixture of compounds 20/21, in a ratio of ca.
2:1, was obtained from 6 according to the procedure described above
1
1
(68%). IR: 1591, 1611 cm (film). Compound 20: H NMR (200 MHz,
CDCl3) selective signals taken from the spectrum of the mixture: 1.32,
1.53 (2s, 6H, 2 CH3), 3.33 (dd, 1H, J = 9.2 Hz, J = 7.1 Hz, H-5a), 3.43
(dd, 1H, J = 9.2 Hz, J = 5.7 Hz, H-5b), 4.52 (d, 1H, J = 3.8 Hz, H-2),
4.66 (d, 1H, J = 15 Hz, CH ), 5.84 (d, 1H, J = 3.8 Hz, H-1), 6.21 (d,
1
1H, J = 15 Hz, OCH ). Compound 21: H NMR (200 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 3.27 (dd,
1H, J = 9.6 Hz, J = 6.8 Hz, H-5a), 3.47 (dd, 1H, J = 9.6 Hz, J = 6.0 Hz,
H-5b), 4.24 (d, 1H, J = 8.1 Hz, CHSi ), 4.49 (d, 1H, J = 3.8 Hz, H-2),
5.88 (d, 1H, J = 3.8 Hz, H-1), 6.52 (d, 1H, J = 8.1 Hz, OCH ). MS
(LSIMS, HR) m/z: [M + Na]+ calcd for C32H38O5SiNa: 553.2386. Found:
553.2403.

Formation of Chiral -Silyl-Vinyl Ethers
337
Anal. Calcd for C32H38O5Si (530.75): C, 72.42; H, 7.22. Found: C,
72.21; H, 7.34.
(E) and (Z) 1,2-O-Isopropylidene-3-O-(20-trimethylsilyl-
vinyl)-5-O-tosyl- -D-xylofuranose (22/23)
A mixture of compounds 22/23, in a ratio of ca. 2.2:1, was obtained
from 7 according to the procedure described earlier (60%). IR: 1592,
1
1611 cm (CH2Cl2). Compound 22: 1H NMR (500 MHz, CDCl3) selec-
tive signals taken from the spectrum of the mixture: 1.32, 1.51 (2s,
6H, 2 CH3), 4.53 (d, 1H, J = 3.7 Hz, H-2), 4.68 (d, 1H, J = 15.1 Hz,
CH ), 5.87 (d, 1H, J = 3.7 Hz, H-1), 6.18 (d, 1H, J = 15.1 Hz, OCH ).
Compound 23: 1H NMR (500 MHz, CDCl3) selective signals taken from
the spectrum of the mixture: 1.49 (2s, 2H, 2
CH3), 4.37 (d, 1H,
J = 8.1 Hz, CHSi ), 4.50 (d, 1H, J = 3.6 Hz, H-2), 5.86 (d, 1H, J =
3.6 Hz, H-1), 6.48 (d, 1H, J = 8.2 Hz, OCH ). MS (LSIMS, HR) m/z:
[M + Na]+ calcd for C20H30O7SiSNa: 465.13792. Found: 465.13829.
Anal. Calcd for C20H30O7SiS (442.62): C, 54.27; H, 6.83. Found: C,
54.24; H, 6.93.
(E) and (Z) 1,2-O-Isopropylidene-3-O-methyl-5-O-(20-
trimethylsilyl-vinyl)-6-O-trityl- -D-glucofuranose (24/25)
A mixture of compounds 24/25, in a ratio of ca. 6.5:1, was obtained
from 13 according to the procedure described for compounds 18/19
1
(84%). IR 1613 cm (film). Compound 24: 1H NMR (200 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 1.29, 1.44
(2s, 6H, 2
CH3), 3.37 (s, 3H, OMe), 3.74 (d, 1H, J = 2.8 Hz, H-3),
4.51 (d, 1H, J = 3.8 Hz, H-2), 4.69 (d, 1H, J = 14.5 Hz, CH ), 5.79 (d,
1H, J = 3.8 Hz, H-1), 6.40 (d, 1H, J = 14.5 Hz, OCH ). Compound 25:
1H NMR (200 MHz, CDCl3) selective signals taken from the spectrum
of the mixture: 1.32, 1.49 (2s, 6H, 2 CH3), 3.38 (s, 3H, OMe), 3.77
(d, 1H, J = 2.9 Hz, H-3), 4.23 (d, 1H, J = 8.5 Hz, CHSi ), 5.90 (d, 1H,
J = 3.8 Hz, H-1), 6.80 (d, 1H, J = 8.5 Hz, OCH ). MS (LSIMS, HR)
m/z: [M + Na]+ calcd for C34H42O6SiNa: 597.26484. Found: 597.26285.
Anal. Calcd for C34H42O6Si (574.81): C, 71.05; H, 7.88. Found: C,
70.78; H, 7.30.
(E) and (Z) 1,2-O-Isopropylidene-3-O-methyl-6-O-(2,4,6-
triisopropylbenzenesulfonyl)-5-O-(20-trimethylsilyl-vinyl)-
-D-glucofuranose (26/27)
A mixture of compounds 26/27, in a ratio of ca. 2.8:1, was ob-
tained from 14 according to the general procedure described for com-
pounds 18/19 (76%). IR: 1602, 1615 cm 1 (film). Compound 26: 1H NMR
(200 MHz, CDCl3) selective signals taken from the spectrum of the

338
R. Lysek et al.
mixture: 3.37 (s, 3H, OMe), 4.47 (dd, 1H, J = 10.8 Hz, J = 2.1 Hz,
H-6b), 4.56 (d, 1H, J = 3.8 Hz, H-2), 4.65 (d, 1H, J = 14.5 Hz, CH ),
5.85 (d, 1H, J = 3.8 Hz, H-1), 6.20 (d, 1H, J = 14.5 Hz, OCH ). Com-
pound 27: 1H NMR (500 MHz, CDCl3) selective signals taken from the
spectrum of the mixture: 3.38 (s, 3H, OMe), 4.04 (dd, 1H, J = 9.0 Hz,
J = 3.2 Hz, H-4), 4.46 (dd, 1H, J = 10.9 Hz, J = 2.0 Hz, H-6b), 5.84 (d,
1H, J = 3.7 Hz, H-1), 6.59 (d, 1H, J 8.3 Hz, OCH ). MS (LSIMS, HR)
m/z: [M + Na]+ calcd for C30H50O8SiSNa: 621.28934. Found: 621.29272.
Anal. Calcd for C30H50O8SiS (598.89): C, 60.20; H, 8.41. Found: C,
60.22; H, 8.52.
(E) and (Z) 1,2-O-Isopropylidene-3-O-methyl-6-O-tosyl-
5-O-(20-trimethylsilyl-vinyl)- -D-glucofuranose (28/29)
A mixture of compounds 28/29, in a ratio of ca. 2.5:1, was obtained
from 15 according to the general procedure described for compounds
1
1
18/19 (71%). IR: 1614 cm (film). Compound 28: H NMR (200 MHz,
CDCl3) selective signals taken from the spectrum of the mixture: 1.30,
1.46 (2s, 6H, 2 CH3), 3.34 (s, 3H, OMe), 4.53 (d, 1H, J = 3.8 Hz, H-
2), 4.58 (d, 1H, J = 14.5 Hz, CH ), 5.81 (d, 1H, J = 3.8 Hz, H-1), 6.11
(d, 1H, J = 14.5 Hz, OCH ). Compound 29: 1H NMR (200 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 1.31, 1.47
(2s, 6H, 2
CH3), 3.35 (s, 3H, OMe), 3.77 (d, 1H, J = 2.9 Hz, H-3),
4.17 (d, 1H, J = 8.3 Hz, CHSi ), 6.54 (d, 1H, J = 8.3 Hz, OCH ).
MS (LSIMS, HR) m/z: [M + Na]+ calcd for C22H34O8SiSNa: 509.16414.
Found: 509.16163.
Anal. Calcd for C22H34O8SiS (486.67): C, 54.29; H, 7.04. Found: C,
54.40; H, 7.13.
(E) and (Z) 3-O-Benzyl-1,2-O-isopropylidene-6-O-(2,4,6-
triisopropylbenzenesulfonyl)-5-O-(20-trimethylsilyl-vinyl)-
-D-glucofuranose (30/31)
A mixture of compounds 30/31, in a ratio of ca. 5.1:1, was obtained
from 16 according to the general procedure described earlier (48%).
1
IR: 1615, 1601 cm (film). Compound 30: 1H NMR (200 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 3.99 (d,
1H, J = 3.2 Hz, H-3), 4.53 (d, 1H, J = 14.6 Hz, CH ), 5.84 (d, 1H, J =
3.7 Hz, H-1), 6.18 (d, 1H, J = 14.6 Hz, OCH ). Compound 31: 1H NMR
(500 MHz, CDCl3) selective signals taken from the spectrum of the
mixture: 3.97 (d, 1H, J = 3.2 Hz, H-3), 5.83 (d, 1H, J = 3.7 Hz, H-1),
6.55 (d, 1H, J = 8.3 Hz, OCH ). MS (LSIMS, HR) m/z: [M + Na]+ calcd
for C36H54O8SiSNa: 697.32064. Found: 697.32241.
Anal. Calcd for C36H54O8Si (674.96): C, 64.06; H, 8.06. Found: C,
63.51; H, 7.85.

Formation of Chiral -Silyl-Vinyl Ethers
339
(E) and (Z) 3-O-Benzyl-1,2-O-isopropylidene-6-O-tosyl-
5-O-(20-trimethylsilyl-vinyl)- -D-glucofuranose (32/33)
A mixture of compounds 32/33, in a ratio of ca. 4.4:1, was obtained
from 17 according to the general procedure described earlier (50%).
1
IR: 1614, 1602 cm (film). Compound 32: 1H NMR (500 MHz, CDCl3)
selective signals taken from the spectrum of the mixture: 3.98 (d,
1H, J = 3.2 Hz, H-3), 5.89 (d, 1H, J = 3.7 Hz, H-1), 6.11 (d, 1H, J =
1
14.6 Hz, OCH ). Compound 33: H NMR (200 MHz, CDCl3) selec-
tive signals taken from the spectrum of the mixture: 3.97 (d, 1H,
J = 3.2 Hz, H-3), 5.85 (d, 1H, J = 3.7 Hz, H-1), 6.50 (d, 1H, J = 8.3 Hz,
OCH ). MS (LSIMS, HR) m/z: [M + Na]+ calcd for C28H38O8SiSNa:
585.19544. Found: 585.19513.
[2+2]Cycloadditions of chlorosulfonyl isocyanate to 20-
silylvinyl ethers 20/21, and 28/29 were performed according to the
known procedure.1,15
(30S,40R) and (30R,40R) 1,2-O-Isopropylidene-3-O-
(30-trimethylsilyl-azetidin-20-on-40-yl)-5-O-trityl-
-D-xylofuranose (34 and 35)
A mixture of stereoisomers 34 and 35, in a ratio 7.5:1, was obtained
from 20/21 in 17% yield. Unsaturated amide 36 was detected in crude
1
22
post-reaction mixture by H NMR. Compound 34: [ ]D
28.0 (C 1,
CH2Cl2), lit.1 [ ]D 28.3 (C 1, CH2Cl2). Compound 35: Solid foam; [ ]D22
26.7 (C 0.24, CH2Cl2). IR: 1762 cm (CH2Cl2). H NMR (200 MHz,
1
1
CDCl3): 0.14 (s, 9H, SiMe3), 1.37, 1.56 (2s, 6H, 2
CH3), 2.70 (d,
1H, J = 1.5 Hz, H-30), 3.24 (dd, 1H, J = 9.5 Hz, J = 3.7 Hz, H-5a), 3.59
(dd, 1H, J = 9.5 Hz, J = 5.5 Hz, H-5b), 4.04 (d, 1H, J = 3.0 Hz, H-3),
4.31 (m, 1H, H-4), 4.54 (d, 1H, J = 3.8 Hz, H-2), 4.94 (d, 1H, J = 1.5 Hz,
H-40), 5.93 (d, 1H, J = 3.8 Hz, H-1), 6.06 (br s, 1H, NH). MS (EI, HR)
m/z: M+ calcd for 573.2547. Found: 573.2522.
Anal. Calcd for C33H39O6SiN: (573.779): C, 69.08; H, 6.85; N, 2.44.
Found: C, 68.95; H, 6.77; N, 2.60.
(30R,40S) and (30S,40R) 1,2-O-Isopropylidene-3-O-methyl-
6-O-tosyl-5-O-(30-trimethylsilyl-azetidin-20-on-40-yl)-
-D-glucofuranose (37 and 38)
A mixture of stereoisomers 37 and 38, in a ratio ca. 7:1, respec-
tively, was obtained from 28/29 in 15% yield. Unsaturated amide 39
1
was detected in the crude post reaction mixture by H NMR. Spectral
1
data taken for the mixture, IR: 3411, 1778, 1760 cm (CH2Cl2). Com-
1
pound 37: H NMR (500 MHz, CDCl3) selective signals: 5.40 (d, 1H,
J = 4.4 Hz, H-40), 5.78 (d, 1H, J = 3.7 Hz, H-1), 6.14 (br s, 1H, NH).
Compound 38: 1H NMR (500 MHz, CDCl3) selective signals: 5.18

340
R. Lysek et al.
(d, 1H, J = 4.4 Hz, H-40), 5.81 (d, 1H, J = 3.8 Hz, H-1), 6.41 (br s, 1H, NH).
MS (EI, LSIMS) m/z: [M + H]+ calcd for C23H36O9SiSN: 530.18801.
Found: 530.18951.
REFERENCES
[1] R.Lysek, Z. Kaluza, B. Furman, and M. Chmielewski, Tetrahedron, 54, 14065 (1998).
[2] (a) T. K. Sarkar and S. K. Ghosh, Tetrahedron Lett., 28, 2061 (1987); (b) P. Mueller
and N. Pautex, Helv. Chim. Acta, 74, 55 (1991); (c) Z. Z. Song, Z. Y. Zhou, T. C. W.
Mak, and H. N. C. Wong, Angew. Chem., 105, 406 (1993).
[3] S. E. Denmark and A. Thorarensen, J. Am. Chem. Soc., 119, 125 (1997).
[4] (a) N. A. Petasis and I. Akritopoulou, Synlett, 665 (1992); (b) N. A. Petasis, J. P.
Staszewski, and D.-K. Fu, Tetrahedron Lett., 36, 3619 (1995); (c) N. A. Petasis, S.-P.
Lu, E. I. Bzowej, D.-K. Fu, J. P. Staszewski, I. Akritopoulou-Zanze, M. A. Patane,
and Y.-H. Hu, Pure Appl. Chem., 68, 667 (1996).
[5] W. Sowa, Can. J. Chem., 46, 1586 (1968).
[6] M. Spescha, Helv. Chim. Acta, 76, 1832 (1993).
[7] K. Kefurt, Z. Kefurtova, J. Jary, I. Horakova, and M. Marek, Carbohydr. Res., 223,
137 (1992).
[8] Z. Kaluz˙a, B. Furman, and M. Chmielewski, Tetrahedron: Asymmetry, 6, 1719
(1995).
[9] D. H. R. Barton and W. B. Motherwell, J. Chem. Soc., Perkin Trans 1, 1124 (1980).
[10] H. Redlich, J. B. Lenfers, and W. Burns, Liebigs Ann. Chem., 1570 (1985).
[11] (a) L. E. Overman and R. M. Vurk, Tetrahedron Lett., 25, 5739 (1984); (b) M. C.
McIntosh and S. M. Weinreb, J. Org. Chem., 58, 4823 (1993); (c) S. D. Burke, M. E.
Kort, S. M. Strickland, H. M. Organ, and L. A. I. Silks, Tetrahedron Lett., 35, 1503
(1994).
[12] (a) M. A. Brook, Silicon in Organic, Organometallic and Polymer Chemistry
(J. Wiley & Sons, New York, 2000); (b) C. Semeyn, R. H. Blaauw, H. Hiemstra,
and W. N. Speckamp, J. Org. Chem., 62, 3426 (1997).
[13] K. Hintzer, B. Koppenhoefer, and V. Schuring, J. Org. Chem., 47, 3850 (1982).
[14] A. Van Es and W. Stewens, Rec. Trav. Chim. Pays-Bas, 84, 704 (1965).
[15] R.Lysek, B. Furman, Z. Kaluz˙a, and M. Chmielewski, Polish J. Chem., 74, 51 (2000).