Remarkably efficient charcoal-promoted ring-closing carbonylations

Article abstract of DOI:10.1055/s-2006-926340

An efficient, versatile and practical gram-scale preparation of oxazolidinone, imidazolidinone and dioxolanone is achieved. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-2006-926340

PAPER
885
Remarkably Efficient Charcoal-Promoted Ring-Closing Carbonylations
R
N
emarkably Effici
a
ent Synthes
c
is of
O
xazo
i
lidinon
r
es, Imid
a
a
zolidinones and
A
D
ioxolanones louane, Audrey Boutier, Cyriella Baron, Emmanuel Vrancken,* Pierre Mangeney
Université Pierre et Marie Curie-Paris 6, Laboratoire de Chimie Organique (UMR CNRS 7611), Institut de Chimie Moléculaire (FR 2769),
bte 183, 4 place Jussieu, 75252 Paris Cedex 05, France
Fax +33(1)44277567; E-mail: vrancken@ccr.jussieu.fr
Received 14 October 2005
solutions. We decided to transpose it to the ring-closing
Abstract: An efficient, versatile and practical gram-scale prepara-
carbonylation of aminoalcohols. A solution of the ami-
tion of oxazolidinone, imidazolidinone and dioxolanone is
noalcohol 3 (2 mmol, 578 mg) in THF was thus added to
a suspension of diphosgene (0.85 equiv) and activated
charcoal (10 mg) in THF and the resulting mixture was
stirred overnight at room temperature. A simple filtration
through Celite followed by standard workup cleanly af-
fords oxazolidinone 1 in 96% yield (602 mg). Scale-up of
the reaction to 89 mmol of the starting material gave the
desired product with roughly the same yield (89%, 25 g)
achieved.
Key words: oxazolidinones, imidazolidinones, dioxolanones,
phosgenes
Ring-closing carbonylation of vicinal diamines, aminoal-
cohols, and diols is a very useful class of reaction, leading
to highly versatile imidazolidinones, oxazolidinones and
dioxolanones. However, despite the development of many
methodologies, these transformations remain sometimes
challenging.
(
Scheme 2). Noteworthy, the crude product required no
further purification.
O
In the course of our research program directed towards the
study of new allenyl copper reagents, we focused on these
reactions to obtain analytical samples suitable for struc-
ture determinations as well as multi-gram amounts of
chiral inductors such as enantiopure oxazolidinone 1. A
practical synthesis of oxazolidinone 1 reported by Davies
began with the addition of excess PhMgBr to a-amino
methyl ester 2 to afford the corresponding aminoalcohol
Ph
ClCO2CCl3 (0.85 equiv)
activated charcoal (0.5 g)
O
NH
Ph
OH
Ph
H2N
THF, r.t. overnight
Ph
1
Ph
3
Ph
25 g, 89% yield
Scheme 2
Encouraged by this result, we checked the generality of
this reaction with aminoalcohols 4–8 according to
Scheme 2 (Table 1). In all cases, the reaction proceeded
cleanly and the expected oxazolidinones 9–13 were ob-
tained with good to excellent yields. Noteworthy, no race-
3
, followed by a ring-closing carbonylation using 1,1¢-car-
1
bodiimidazole (CDI). However, we were unable to
achieve this last transformation on the gram scale. Other
attempts using diphosgene with triethylamine in
2
dichloromethane gave poorly reproducible results
5
mization was observed during the process, giving a
(
Scheme 1).
smooth access to enantiopure oxazolidinones. In that way,
the Evans oxazolidinone 10 was obtained, without any pu-
rification, quantitatively and in a suitable analytical puri-
ty. In selected cases a smooth heating to 50 °C was needed
to ensure a good conversion (entries 1 and 4) and we ob-
served that the presence of triethylamine as additive had a
beneficial effect (entries 2 and 5). The reaction seemed to
be insensitive to the nature of the starting aminoalcohol
and particularly to the steric hindrance of the nitrogen
substituent. Indeed, even aminoalcohol 8 where nitrogen
bears a bulky tert-butyl group was converted into the cor-
responding oxazolidinone 13 with high yield. In this case
the presence of triethylamine was required.
O
Ph
O
Ph
Ph
(
ii)
(
i)
OH
Ph
O
NH
Ph
H2N
H N
9
0%
2
Ph
OMe
2
3
Ph
1
Scheme 1 Reagents and conditions: (i) PhMgBr (6.5 equiv), Et O;
2
(
ii) CDI, CH Cl or diphosgene, Et N, CH Cl .
2 2 3 2 2
An alternate protocol of ring-closing carbonylation has
been reported for the synthesis of N-carboxy anhydrides
from a-aminoacids. This two-step reaction implies an in
situ decomposition of diphosgene promoted by a catalytic
amount of activated charcoal and the subsequent cycliza-
tion of the amino acid by the resulting phosgene. This pro-
cedure allows an easy and safe access to phosgene
3
,4
3
Next, we decided to expand the scope of the method. The
reaction conditions were examined with various vicinal
diols. The results are summarized in Table 2. As expected
for the use of these less-nucleophilic reagents, longer re-
action times were often required to ensure good levels of
conversion. For reaction times above 72 hours (entries 4
and 5), a significant amount of 4-chlorobutyl chlorofor-
mate was formed, resulting from the ring opening of the
SYNTHESIS 2006, No. 5, pp 0885–0889
x
x
.
x
x
.2
0
0
6
Advanced online publication: 08.02.2006
DOI: 10.1055/s-2006-926340; Art ID: Z19905SS
Georg Thieme Verlag Stuttgart · New York
©

8
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N. Alouane et al.
PAPER
Table 1 Ring-Closing Carbonylations of Aminoalcohols 4–8
Entry
1
Aminoalcohol
Product
Conditions
50 °C, 48 h
Yield (%)
96a
O
NH2
HN
Ph
O
OH
Ph
4
9
O
NH2
Et N (7 equiv)
HN
i-Pr
O
3
97b
93a
86a
91a
2
3
4
5
OH
i-Pr
5
0 °C, 48 h
5
1
0
O
NH2
Ph
HN
O
r.t., 16 h
Me
OH
Me
Ph
6
1
1
O
Me
NH
Ph
MeN
Me
O
50 °C, 16 h
Me
OH
Ph
7
1
2
O
t-Bu NH
OH
Ph
Et N (7 equiv)
t-BuN
O
3
5
0 °C, 72 h
Ph
8
1
3
a
Isolated yield.
b
The analytical purity of the crude compound was satisfactory.
THF by phosgene. This side product was quantitatively diphosgene. To avoid the formation of this side product
converted into 4-chlorobutanol after standard workup and and thus reduce the quantities of diphosgene used, the re-
easily removed under reduced pressure (0.1 mm Hg). action was conducted in THP with 0.85 equivalent of
However, due to this side reaction, further addition of diphosgene and we were pleased to note that under these
diphosgene until the completion of the reaction was need- conditions the desired product 27 was obtained after only
ed. Nevertheless, the expected dioxolanones 21–25 were 96 hours with an excellent yield (98%, entry 7). Only trace
cleanly provided in high yield, ranging from 80% to 93%. amount of 5-chloropentanol was detected in the crude
Interestingly, the presence of sensitive groups such as es- mixture and was easily removed under high vacuum to
ters, propargylic alcohols or (trimethylsilyl)acetylenic give the analytically pure imidazolidinone 27. On the con-
moiety is compatible with our methodology since no deg- trary, almost no reaction occurred in dichloromethane.
radation or epimerization products were detected in the
crude mixture (entries 3–5).
In conclusion, we have developed a practical, safe and
versatile methodology for the preparation of oxazolidino-
Finally, the observation of an easy reaction with the hin- nes, dioxolanones and imidazolidinones in high yield. In
dered aminoalcohol 8 prompted us to examine the limits many cases, no further purifications are needed. Further-
of the method. The reactivity of diamines was thus ad- more, this methodology still works even with very bulky
dressed. As expected, imidazolidinone 26 was easily ob- substituents.
tained from the Corey diamine 19 (Table 2, entry 6). More
challenging was the case of the very sterically hindered
D,L-diamine 20. Even in this case, the reaction proceeded
efficiently leading to the formation of the corresponding trogen. All moisture-sensitive reactants were handled under argon.
Experiments were carried out under dry argon. All glassware was
dried at 120 °C and assembled while hot under a stream of dry ni-
oxazolidinone 27 in a good yield (78%). The completion The flask was equipped with an internal thermometer, an argon in-
let, and a septum cap. THF and tetrahydropyran (THP) were dis-
of the reaction required a longer reaction time (4 h) and
tilled from sodium/benzophenone ketyl. Column chromatography
then these conditions resulted in the formation of high
was performed on silica gel Si 60 (0.015–0.040 mesh). Melting
points were measured with a Stuart Scientific 7SMP3 and are un-
quantities of 4-chlorobutyl chloroformate, which necessi-
tated the portionwise addition of 1.7 equivalents of
Synthesis 2006, No. 5, 885–889 © Thieme Stuttgart · New York

PAPER
Remarkably Efficient Synthesis of Oxazolidinones, Imidazolidinones and Dioxolanones
887
Table 2 Synthesis of Dioxolanones 21–25
Entry
1
Reactant
Product
Conditions
50 °C, 48 h
Yield (%)
93a
O
OH
Ph
O
O
O
OH
Ph
Ph
14
2
1
O
OH
O
88a
2
3
50 °C, 72 h
Ph
OH
OH
Ph
Ph
15
2
2
O
CO2Et
90b
O
EtO2C
O
EtO C
2
50 °C, 120 h
OH
CO2Et
16
2
3
O
OH
O
O
Cy
Et N (7 equiv)
3
80b
4
5
0 °C, 120 h
Cy
TMS
OH
17
TMS
2
4
O
OH
O
O
Cy
Et N (7 equiv)
3
87b
5
6
5
0 °C, 120 h
Cy
Et
OH
18
Et
2
5
O
NH2
Ph
Et N (7 equiv)
3
HN
Ph
NH
Ph
88b
Ph
5
0 °C, 16 h
NH2
19
2
6
O
NHtBu
Ph
Et N (7 equiv)
3
98a,c
t-BuN
Ph
Nt-Bu
Ph
7
Ph
5
0 °C, 96 h
NHt-Bu
20
2
7
a
The analytical purity of the crude compound was satisfactory.
Isolated yield.
THP was used as solvent instead of THF.
b
c
corrected. Optical rotations were measured at 20 °C with a Perkin-
Elmer 343 polarimeter. IR data were recorded on a Bruker Tensor
General Procedure
Method A
1
13
2
7 instrument. H NMR spectra were recorded at 400 MHz, and
C
To a suspension of diphosgene (0.20 mL, 1.7 mmol), and activated
charcoal (10 mg) in anhyd THF (10 mL), was added aminoalcohol
or diol or diamine (2 mmol) in THF (10 mL). The reaction mixture
was stirred at 50 °C until no starting material could be detected by
NMR. The solution was then filtered through Celite, quenched with
sat. NaHCO (30 mL) and extracted with Et O. The combined or-
NMR spectra were recorded at 100 MHz, in CDCl as solvent on a
3
Bruker Ultra Shield 400 spectrometer. Chemical shifts are reported
1
13
in ppm (reference CDCl for H NMR and C NMR). Microanaly-
3
ses were performed by ICSN-CNRS, Gif-sur-Yvette, France.
3
2
ganic layers were washed with brine, dried with MgSO and filtered
4
off. The solvents were removed under reduced pressure to afford the
corresponding oxazolidinone or dioxolanone or imidazolidinone.
Synthesis 2006, No. 5, 885–889 © Thieme Stuttgart · New York

8
88
N. Alouane et al.
PAPER
–
1
When needed, the crude product was purified by flash chromatog-
raphy (FC) on silica gel.
IR (neat): 3244, 1710 cm .
1
H NMR (400 MHz, CDCl ): d = 0.79 (d, J = 6.6 Hz, 3 H, CH ), 4.19
m, 1 H, H-4), 5.68 (d, J = 8.1 Hz, 1 H, H-5), 7.04 (s, 1 H, NH),
.26–7.39 (m, 5 H, Ph).
3
3
(
7
Method B
To a suspension of diphosgene (0.20 mL, 1.7 mmol), Et N (2 mL)
3
1
3
C NMR (100 MHz, CDCl ): d = 17.5, 52.5, 81.1, 125.8, 128.2,
and activated charcoal (10 mg) in anhyd THF (10 mL), was added
aminoalcohol or diol or diamine (2 mmol) in THF (10 mL). The re-
action mixture was stirred at 50 °C until no starting material could
be detected by NMR. Workup procedure as for method A was fol-
lowed.
3
1
28.5, 135.1, 160.1.
Anal. Calcd for C H NO : C, 67.78; H, 6.26; N, 7.90; O, 18.06.
Found: C, 67.78; H, 6.26; N, 7.65.
1
0
11
2
(
4S,5S)-3,4-Dimethyl-5-oxazolidin-2-one (12)
This compound was prepared according method A, using (1S,2S)-
+)-pseudoephedrine (330 mg, 2 mmol). Oxazolidin-2-one 12 (328
mg, 86%) was obtained as a pale yellow solid without further puri-
(
4R)-4,5,5-Triphenyloxazolidin-2-one (1)
This compound was prepared according to method A, using (R)-2-
amino-1,2,2-triphenylethanol (25.9 g, 89 mmol). Oxazolidin-2-one
(
1
(25.0 g, 89%) was obtained as a white solid without further puri-
20
8
25
fication; mp 47 °C; [a] +37 (c = 1.00, CHCl ) {Lit. [a] +36.7
(c = 0.98, CHCl )}.
3
D
3
D
2
0
1b
25
fication; mp 245 °C; [a] +198 (c = 1.00, CHCl ) {Lit. [a]D
+
D
3
218 (c = 1.00, CHCl )}.
3
IR (neat): 3479, 1737 cm–1.
1
–
1
IR (neat): 274, 1755, 1727 cm .
H NMR (400 MHz, CDCl ): d = 1.19 (d, J = 6.3 Hz, 3 H, CH ), 2.70
3
3
1
H NMR (400 MHz, CDCl ): d = 5.54 (s, 1 H, CH), 5.64 (s, 1 H,
3
(s, 1 H, H-4), 3.39 (m, 1 H, H-5), 4.74 (d, J = 6.3 Hz, 3 H, NCH ),
3
NH), 7.08–7.71 (m, 15 H, Ph).
7
13
.19–7.33 (m, 5 H, Ph).
1
3
C NMR (100 MHz, CDCl ): d = 65.8, 90.7, 126.2, 126.5, 127.3,
3
C NMR (100 MHz, CDCl ): d = 17.1, 28.6, 61.1, 82.3, 125.9,
3
28.8, 128.9, 137.6, 157.7.
1
27.5, 127.8, 128.3, 128.4, 128.5, 128.7, 137.1, 138.8, 142.8, 158.2.
1
Anal. Calcd for C H NO : C, 79.98; H, 5.43; N, 4.44; O, 10.15.
Found: C, 79.95; H, 5.43; N, 4.42.
2
1
17
2
Anal. Calcd for C H NO : C, 69.09; H, 6.86; N, 7.32; O, 16.73.
Found: C, 67.69; H, 6.86; N, 6.95.
1
1
13
2
(
4S)-4-Phenyloxazolidin-2-one (9)
This compound was prepared according to method A, using (S)-(+)-
-phenylglycinol (274 mg, 2 mmol). Purification by FC (pentane–
Et O, 50:50) gave oxazolidin-2-one 9 (313 mg, 96%) as a white sol-
(
5S)-3-tert-Butyl-5-oxazolidin-2-one (13)
This compound was prepared according to method B, using (S)-2-
tert-butylamino)-1-phenylethanol (386 mg, 2 mmol). Purification
by FC (pentane–Et O, 50:50) gave oxazolidin-2-one 13 (400 mg,
2
(
2
2
20
6
25
id; mp 114 °C; [a] +55 (c = 1.00, CHCl ) {Lit. [a] +59 (c =
1
20
9
25
D
3
D
91%) as a pale yellow oil; [a] +59 (c = 1.20, CHCl ) {Lit. [a]
+49 (c = 1.00, CHCl )}.
D
3
D
.00, CHCl )}.
3
3
–
1
IR (neat): 3229, 1701 cm .
IR (neat): 2974, 1736 cm–1.
1
1
H NMR (400 MHz, CDCl ): d = 4.14 (dd, J = 6.8, 8.6 Hz, 1 H, H-
3
H NMR (400 MHz, CDCl ): d = 1.39 [s, 9 H, (CH ) ], 3.44 (dd,
3
3 3
5
), 4.71 (t, J = 8.6 Hz, 1 H, H-4), 4.95 (t, J = 8.6 Hz, 1 H, H-5), 6.78
J = 7.8, 8.6 Hz, 1 H, H-4), 3.96 (t, J = 8.6 Hz, 1 H, H-4), 5.35 (t,
J = 7.8 Hz, 1 H, H-5), 7.28–7.55 (m, 5 H, Ph).
(s, 1 H, NH), 7.28–7.41 (m, 5 H).
1
3
C NMR (100 MHz, CDCl ): d = 56.4, 72.5, 126.0, 128.7, 129.1,
13
3
C NMR (100 MHz, CDCl ): d = 27.4, 51.1, 53.5, 73.5, 125.5,
3
28.7, 128.8, 138.9, 156.8.
1
39.7, 160.3.
1
Anal. Calcd for C H NO : C, 66.25; H, 5.56; N, 8.58; O, 19.61.
Found: C, 66.38; H, 5.65; N, 8.52.
9
9
2
Anal. Calcd for C H NO : C, 71.21; H, 7.81; N, 6.39; O, 14.59.
Found: C, 69.29; H, 7.75; N, 6.55.
1
3
17
2
(
4S)-4-Isopropyloxazolidin-2-one (10)
(
4S)-4-Phenyl[1,3]dioxolan-2-one (21)
This compound was prepared according to method B, using (S)-(+)-
2
This compound was prepared according to method A, using (S)-1-
phenylethane-1,2-diol (276 mg, 2 mmol). Dioxolan-2-one 21 (306
mg, 93%) was obtained as a white solid without further purification;
mp 64 °C; [a]D –44 (c = 1.00, CHCl ) {Lit. [a]D –31 (c = 1.00,
CHCl )}.
-amino-3-methyl-1-butanol (0.22 mL, 2 mmol). Oxazolidin-2-one
1
0 (250 mg, 97%) was obtained as a pale yellow solid without fur-
2
0
6
25
ther purification; mp 59 °C; [a] –18 (c = 1.00, EtOH) {Lit. [a]
–
20
10
20
D
D
3
17 (c = 1.02, EtOH)}.
3
–
1
IR (neat): 3263, 1720 cm .
IR (neat): 3354, 2926, 1773 cm–1.
1
H NMR (400 MHz, CDCl ): d = 0.87 (d, J = 6.6 Hz, 3 H, CH ), 0.93
1
3
3
H NMR (400 MHz, CDCl ): d = 4.34 (t, J = 8.3 Hz, 1 H, H-5), 4.81
3
(
d, J = 6.6 Hz, 3 H, CH ), 1.63 (m, 1 H, H-4), 3.59 (q, J = 6.6, 8.3
3
(t, J = 8.3 Hz, 1 H, H-5), 5.68 (t, J = 8.3 Hz, 1 H, H-4), 7.22–7.55
Hz, 1 H, CH), 4.06 (dd, J = 6.3, 8.6 Hz, 1 H, H-5), 4.41 (t, J = 8.6
Hz, 1 H, H-5), 7.22 (s, 1 H, NH).
(
1
m, 5 H, Ph).
3
C NMR (100 MHz, CDCl ): d = 71.3, 78.1, 125.9, 129.3, 129.7,
3
1
3
C NMR (100 MHz, CDCl ): d = 17.63, 17.94, 32.69, 58.42, 68.62,
3
135.9, 155.0.
1
60.8.
Anal. Calcd for C H O : C, 65.85; H, 4.91; O, 29.24. Found: C,
65.82; H, 4.97.
9
8
3
Anal. Calcd for C H NO : C, 55.80; H, 8.58; N, 10.84; O, 24.78.
Found: C, 55.81; H, 8.64; N, 10.73.
6
11
2
(
4R,5R)-4,5-Diphenyl[1,3]dioxolan-2-one (22)
This compound was prepared according to method A, using
1R,2R)-1,2-diphenylethane-1,2-diol (363 mg, 1.7 mmol). Diox-
olan-2-one 22 (460 mg, 96%) was obtained as a pale yellow solid
(
4R,5S)-4-Methyl-5-phenyloxazolidin-2-one (11)
This compound was prepared according to method A, using
(
(
purification; mp 89 °C; [a] –166 (c = 1.00, CHCl ) {Lit. [a]
–
(
1R,2S)-(–)-norephedrin (300 mg, 2 mmol). Oxazolidin-2-one 11
329 mg, 93%) was obtained as a pale yellow solid without further
20
without further purification; mp 122 °C; [a]
CHCl ) {Lit. [a]D +66 (c = 1.05, CHCl )}.
IR (neat): 2945, 2857, 1813 cm–1.
+66 (c = 1.00,
D
2
0
7
20
11
20
D
3
D
3
3
170 (c = 1.20, CHCl )}.
3
Synthesis 2006, No. 5, 885–889 © Thieme Stuttgart · New York

PAPER
Remarkably Efficient Synthesis of Oxazolidinones, Imidazolidinones and Dioxolanones
889
1
H NMR (400 MHz, CDCl ): d = 5.46 (s, 2 H, H-4, H-5), 7.17–7.64
FC (pentane–Et O, 20:80) gave imidazolidin-2-one 26 (420 mg,
3
2
2
0
(
1
m, 10 H, Ph).
88%) as a pale yellow solid; mp 156 °C; [a]
–54 (c = 1.00,
+58.6 (c = 1.06, CHCl ) for the R,R deriva-
3
D
1
2
20
3
CHCl
tive}.
3
) {Lit. [a]
D
C NMR (100 MHz, CDCl ): d = 85.4, 126.2, 129.3, 129.8, 134.8,
3
1
54.1.
–
1
IR (neat): 3210, 1698 cm .
Anal. Calcd for C H O : C, 74.99; H, 5.03; O, 19.98. Found: C,
7
15
12
3
1
1.94; H, 6.07.
H NMR (400 MHz, CDCl ): d = 4.54 (s, 2 H, H-4, H-5), 6.08 (s, 2
3
H, NH), 7.38–7.25 (m, 10 H, Ph).
(
4S,5S)-2-Oxo[1,3]dioxolane-4,5-dicarboxylic Acid Diethyl Es-
13
C NMR (100 MHz, CDCl ): d = 65.9, 126.5, 128.3, 128.8, 140.4,
3
ter (23)
1
63.5.
This compound was prepared according to method A, using (–)-di-
ethyl D-tartrate (0.34 mL, 2 mmol) and adding further diphosgene
Anal. Calcd for C H N O: C, 75.61; H, 5.92; N, 11.76; O, 6.71.
Found: C, 72.07; H, 5.92; N, 10.83.
15 14
2
(0.03 mL, 0.13 equiv) after 72 h. Purification by FC (pentane–Et O,
2
6
0:40) gave dioxolan-2-one 23 (420 mg, 90%) as a pale yellow oil;
20
1,3-Di-tert-butyldiphenylimidazolidin-2-one (27)
[
a]D +23 (c = 1.30, CHCl3).
This compound was prepared according to method B, using N,N-di-
tert-butyl-1,2-diphenylethane-1,2-diamine (649 mg, 2 mmol) and
freshly distilled THP instead of THF as solvent. Imidazolidin-2-one
27 (686 mg, 98%) was obtained as a white solid without further pu-
rification; mp 140 °C.
–
1
IR (neat): 2855, 1751, 1840 cm .
1
H NMR (400 MHz, CDCl ): d = 1.37 (t, J = 7.1 Hz, 6 H, CH ), 4.37
q, J = 7.1 Hz, 4 H, COOCH ), 5.12 (s, 2 H, H-4, H-5).
3
3
(
2
1
3
C NMR (100 MHz, CDCl ): d = 14.0, 63.4, 74.8, 167.9, 166.1.
3
–
1
IR (neat): 3205, 1742 cm .
Anal. Calcd for C H O : C, 46.56; H, 5.21; O, 48.24. Found: C,
4
19
12
7
1
6.65; H, 5.21.
H NMR (400 MHz, CDCl ): d = 1.29 [s, 18 H, (CH ) ], 4.21 (s, 2
3
3 3
H, H-4, H-5), 7.13–7.51 (m, 10 H, Ph).
4
-Cyclohexyl-5-trimethylsilanylethynyl[1,3]dioxolan-2-one (24)
13
C NMR (100 MHz, CDCl ): d = 28.8, 53.7, 65.5, 125.5, 127.8,
3
This compound was prepared according to method B, using 1-cy-
clohexyl-4-trimethylsilanyl-but-3-yne-1,2-diol (72 mg, 0.3 mmol)
and adding further diphosgene (0.08 mL, 0.3 equiv) after 72 h. Pu-
1
29.0, 145.0, 159.7.
Anal. Calcd for C H N O: C, 78.82; H, 8.63; N, 7.99; O, 4.56.
Found: C, 78.80; H, 8.64; N, 7.99.
24 33
2
rification by FC (pentane–Et O, 50:50) gave dioxolan-2-one 24 (64
2
mg, 80%) as a pale yellow oil.
–
1
IR (neat): 2923, 2852, 1813 cm .
Acknowledgment
1
H NMR (400 MHz, CDCl ): d = 0.23 [s, 9 H, (CH ) ], 0.88–2.19
m, 11 H, Cy), 4.32 (dd, J = 7.3, 8.6 Hz, 1 H, H-5), 5.27 (d, J = 7.3
3
3 3
Thanks to Prof. A. Alexakis for helpful discussions and encourage-
ment.
(
Hz, 1 H, H-4).
1
3
C NMR (100 MHz, CDCl ): d = 0.00, 25.6, 25.8, 26.5, 28.7, 29.1,
3
3
9.6, 70.6, 83.2, 95.9, 98.2, 162.7.
References
Anal. Calcd for C H O Si: C, 63.12; H, 8.32; O, 18.02; Si, 10.54.
Found: C, 63.17; H, 8.38.
(1) (a) Davies, S. G.; Sanganee, H. J. Tetrahedron: Asymmetry
1995, 6, 671. (b) Bull, S. D.; Davies, S. G.; Jones, S.;
Sanganee, H. J. J. Chem. Soc., Perkin Trans. 1 1999, 387.
(2) O’Hagan, D.; Tavasli, M. Tetrahedron: Asymmetry 1999,
10, 1189.
(3) Katakai, R.; Iizuka, Y. J. Org. Chem. 1985, 50, 715.
(4) Tang, L.; Deng, L. J. Am. Chem. Soc. 2002, 124, 2870.
(5) By comparison with optical rotation values reported in the
literature (see experimental section).
1
4
22
3
4
-But-1-ynyl-5-cyclohexyl[1,3]dioxolan-2-one (25)
This compound was prepared according to method B, using 1-cy-
clohexylhex-3-yne-1,2-diol (135 mg, 0.69 mmol). Purification by
FC (pentane) gave dioxolan-2-one 25 (135 mg, 87%) as a pale yel-
low oil.
–
1
IR (neat): 2927, 2854, 1802 cm .
(
6) Prindgen, L. N.; Prol, J.; Alexander, B.; Gillyard, L. J. Org.
Chem. 1989, 54, 3231.
1
H NMR (400 MHz, CDCl ): d = 1.18 (t, J = 7.6 Hz, 3 H, CH ),
3
3
1
.94–2.17 (m, 11 H, Cy), 2.29 (dq, J = 2.0, 7.3 Hz, 2 H, CH ), 4.29
2
(7) Cutugno, S.; Martelli, G.; Negro, L.; Savoia, D. Eur. J. Org.
Chem. 2001, 517.
(8) Moreno-Manas, M.; Padros, I. J. Heterocycl. Chem. 1993,
(
dd, J = 7.3, 8.8 Hz, 1 H, H-5), 5.26 (dt, J = 2.0, 7.3 Hz, 1 H, H-4).
1
3
C NMR (100 MHz, CDCl ): d = 13.3, 14.5, 25.1, 25.3, 25.6, 28.1,
3
2
8.6, 38.8, 70.4, 70.7, 82.9, 93.9, 154.2.
30, 1235.
(9) Fadel, A.; Salauen, J. Tetrahedron Lett. 1988, 29, 6257.
Anal. Calcd for C H O : C, 73.34; H, 9.41; O, 17.24. Found: C,
13
18
3
(
(
10) Barton, P.; Page, M. I. Tetrahedron 1992, 48, 7731.
11) Superchi, S.; Donnoli, M. I.; Proni, G.; Spada, G. P.; Rosini,
C. J. Org. Chem. 1999, 64, 4762.
7
3.45; H, 9.40.
(
4S,5S)-Diphenylimidazolidin-2-one (26)
This compound was prepared according to method B, using (1S,2S)-
,2-diphenylethane-1,2-diamine (424 mg, 2 mmol). Purification by
(
12) Shankhavasi, W.; Yamamoto, M.; Kohmoto, S.; Yamada, K.
Bull. Chem. Soc. Jpn. 1991, 64, 1425.
1
Synthesis 2006, No. 5, 885–889 © Thieme Stuttgart · New York