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Ethyl Lithiodiazoacetate.

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C = N-c
NaCN/C,H,OH
H ~ - C O ~ C ~ H ~
x.
(1 )
!
R
..
:y
NaO
f 3)
Rl-6-C -C 02C zH5
A 2
..
*
:c11
n',,,c=o
Na@
..?.
C = N - C H - COzC 2H5
Na"
O@N
R'#COzC2H5
K2H
(5)
1
CHOH
A
H
A
R1-!&C0zC2H5
J
RZR3
(6 )
EthyI-2-oxazoline-4-carboxylates
(61 prepared.
accessible diazomethyl compounds. Since a C-lithium atom
is replaceable by a variety of other substituents[31, we have
directed our attention toward possible routes leading from
diazo compounds t o C-lithium derivatives c41.
We have now found that ethyl lithiodiazoacetate (2) is obtained when a) diethyl mercuriobis(diazoacetate) 151 ( I ) in
tetrahydrofuran is allowed t o react at ca. -70 "C with phenylo r butyllithium or with lithium thiolates, o r b) ethyl diazoacetate (3) is metalated at -1lOOC in ether or ether/tetrahydrofuran. The lithium compound (2) is stable only below
-5O0C[61; it can be intercepted, e.g., by trialkylstannyl or
trialkylsilyl chlorides, by carbonyl compounds, or by alkyl
halides and thus be utilized in preparative work. Since method
a) is relatively involved and not without attendant danger,
owing to the poisonous nature of the mercury compounds
formed, metalation according to b) is probably the more
suitable method for preparative purposes.
H
H
H
H
H
H
H
CH3 [b]
CH3 [b]
CH3 [bl
30
40
15
-I0
0
reflu,
30
30
reflu,
25
53
55
72
15[dl
71
47
75
67
70
0.4 : 1 [cl 86
0.5
0.5
1
0.5
0.5
1
RLi
0.5
1
1
0.5
wz
Li-C-C02C2H 5
(2)
Preparation and reactions of (2).
Intercepting
reagent
Received: January 22, 1970
[Z 147a IEI
German version: Angew. Chem. 82, 290 (1970)
_ _ ~
~~
[*I Dip1.-Chem. D.
Hoppe and Prof. Dr. U. Schollkopf
Organisch-Chemisches Institut der Universitat
34 Gottingen, Windausweg 2 (Germany)
[l] Syntheses with u-Metalated Isocyanides, Part 5. - Part 4:
U.Schollkopf and D . Hoppe, Angew. Chem. 82, 253 (1970);
Angew. Chem. internat. Edit. 8, 236 (1970).
121 Cf. S . H . Pines, S. Karady, M . A . Kozlowski, and M . Sletzinger, J. org. Chemistry 33, 1762 (1968); D. F. Elliot, J. chem.
SOC.(London) 1949, 589; J . W. Cornforth in R . C . Elderfield:
Heterocyclic Compounds. Wiley, New York 1957, Vol. 5,
p. 377ff.; U.Schollkopf and D. Hoppe, unpublished.
[3] For conversion into cysteine derivatives, see E . M . Fry,
J. org. Chemistry I S , 438 (1950); for conversion into cycloserines, see C . H . Stammer, A . N . Wilson, C. F. Spencer, F. W.
Bachelor, F. W . Holly, and K. Folkers, J. Amer. chem. SOC.79,
3236 (1957).
[41 Cf. U. Schollkopf, F. Gerhart, and R . Schroder, Angew.
Chem. 81, 701 (1969); Angew. Chem. internat. Edit. 8, 672
(1969).
151 F. Gerhartand U.Schollkopf,Tetrahedron Letters1968,6231.
161 I. Ugi, U. Fetzer, U. Eholzer, H. Knupfer, and K. Offermann, Angew. Chem. 77, 492 (1965); Angew. Chem. internat.
Edit. 4 , 472 (1965).
Ethyl Lithiodiazoacetate111
By Ulrich Schollkopf and Hubert Frasnelli[*]
In spite of the extensive work that has been carried out in
diazo chemistry (21 there is still a lack of methods available
for exchange of ligands attached t o the carbon atom of readily
1 No. 4
Interception
product
Yield (%)
in m iod
a
b
I5
52
-
resulting solution allowed t o stand for 30mins at O°C,
filtered, and the filtrate fractionated. 6.3 g (72%) of
b.p. 112 'C/0.2 torr (according t o the N M R spectrum > 95 %
truns form), is obtained [NMR spectrum (CC14): =CH, T =
3.1 (d, J = 2 Hz); IR spectrum (film): 1620cm-1 (vC=N),
1735 cm-1 (vCO)].
Angew. Chem. internat. Edit. f Vol. 9 (1970)
- RZHU
>10:1
>20: 1
>10:1
>lo: 1
[a] HCHO used as paraformaldehyde.
[b] With ethyl a-isocyanopropionate.
[cl cis and trans refer to ethoxycarbonyl and phenyl.
[d] Polymerizes on distillation; crude yield higher.
.
a
$;'z
H g(-C-C02C2H , )2
CH2=CH-CHzI
CsHsCHO
cyclohexanone
ethyl trimethylsilyldiazoacetate
ethyl trimethylsilyldiazoacetate
ethyl trimethylsilyldiazoacetate
ethyl trimethylsilyldiazoacetate
ethyl tributylstannyldiazoacetate
ethyl benzoyldiazoacetate
ethyI 2-diazopropionate
ethyl 2-diazo4-pentenoate
ethyl 2-diazo-3hydroxy-3-phenylpropionate
ethyl 2-diazo-2-( 1hydroxycyclohexy1)acetate
ethyl 2-diazo-3hydroxy-3-phenylbutyrate
47
40
25
61
50
20
45
35
45
41
62
50
Ethyl 2-diazo-3-hydroxy-3-phenylpropionute
A solution containing 47 mmoles of butyllithium (21.5ml of
a 2.2 M solution in pentane) precooled t o -70 OC is added
dropwise at -110OC t o a solution of ethyl diazoacetate
(5.47 g, 47 mmoles) in ether (150 ml) and tetrahydrofuran
(50 ml) over a period of 30 min. A solution of benzaldehyde
(5 g, 47 mmoles) in tetrahydrofuran (30 ml) which has been
cooled t o -70 OC is then added dropwise at -110 OC and the
reaction mixture is allowed to warm t o -25 'C, whereupon a
solution of glacial acetic acid (2.85 g, 47 mrnoles) in tetrahydrofuran (30 ml) that has been cooled t o -7OOC is also
added. On reaching room temperature, the solution is filtered
and the solvent removed under water-pump vacuum (rotary
evaporator, 30 "C).The residue is taken up in 500 ml of light
petroleum (b.p. 4 S 5 0 "C) and shaken with cu. 1 g of active
charcoal. After filtration the solvent is removed under waterpump vacuum. There remained 4.3 g (41 %) of crude ethyl
2-diazo-3-hydroxy-3-phenylpropionate[IR spectrum (film):
3500 (vOH), 2100 ( v N ~ ) ,1680 (vC0) cm-1; NMR spectrum
301
-
(CC14): -i
2.52 (m), 4.24 (s), 5.82 (s), 5.4 (q), 8.77 (t)]. A part of the residue was purified by chromatography on
aluminum oxide (neutral, activity grade 3), elution with light
petroleum first affording a little benzaldehyde and subsequent elution with ether yielding the diazo compound.
On solvolysis of ( I ) in non-buffered 50% aqueous ethanol
(75 "C, 4 h) we obtained 76% of ( 4 ) , 1 4 % of (5),1.5% of ( 6 ) ,
2 % of (7), 1.5% of ( 8 ) , and 5 % of I-ethoxy-2,3-dimethyl2-butene (9).
Received: February 2, 1970
[ Z 147b IE]
German version: Angew. Chem. 82, 291 (1970)
[*] Prof. Dr. U. Schollkopf and Dip1.-Chem. H. Frasnelli
Organisch-Chemisches Institut der Universitat
34 Gottingen, Windausweg 2 (Germany)
[ l ] Metal-Substituted Carbenes and C-Metalated Diazoalkanes, Part 4. - Part 3: (1. Schollkopf, D . Hoppe, N . Rieber,
and V . Jacobi, Liebigs Ann. Chem. 730, 1 (1969).
[2] R . Huisgen, Angew. Chem. 67, 439 (1955); If. Zollinger:
Azo and Diazo Chemistry. Interscience, New York 1961, pp.
68ff.; B. Eistert, M. Regirz, G . Heck, and H. Schwa11 in HoubenWeyl-Miillerr Methoden der Organischen Chemie. Thieme,
Stuttgart 1968, Vol. 1014, p. 482.
[3] Cf. U. Schollkopf in Houben-Weyl-Miillerr Methoden der
Organischen Chemie. Thieme, Stuttgart, Vol. 13, in press. The
scope of the present ester is greater than that of the corresponding silver compound [cf. U . Schollkopf and N . Rieber, Chem.
Ber. 102, 488 (1969)l.
141 Lithiodiazomethane, the only C-lithiodiazoalkane hitherto
described, is a tautomeric compound that reacts mainly as Nlithioisocyanamine; cf. R . Beutler, B. Zeeh, and Eu. Miiller,
Chem. Ber. 102,2636 (1969), and furtherliteraturecited therein.
[51 E. Buchner, Ber. dtsch. chem. Ges. 28, 215 (1894).
[6] Too high a metalation temperature would probably account
for the failure of previous attempts to synthesize lithiodiazoacetic esters [cf. Eu. Miiller and H. Huber-Emden, Liebigs Ann.
Chem. 660, 54 (1962)l.
1-iert-Butylvinyl Trifluoromethanesulfonate:
Solvolysis andRearrangementvia aVinyl Cation[**]
By Antonio Garcia Martinez, Michael Hanack, Richard H .
Summerville, Paul von Rag& Schleyer, and Peier J . Stang [*I
y 3
YH3,CH,
H3C,
/CH3
H3C-C-C-CH3 + HO-C-C+
+
,C=C
I II
I
CHZ
H3C
\CH, -OC,H,
CH,
H3C 0
(7)
(8)
9)
The formation of the rearranged products (51, ( 6 ) , (8),and
( 9 ) proves the intermediacy of a viny1 cation (Z), which is
converted into the more stable ion (3) by migration of a
methyl group. (3) yields the butadiene (5) by elimination,
and the ethers (6) and (91, as well as the alcohol ( 8 ) , by substitution. The major product ( 4 ) can, in principle, also arise
from the vinyl cation (2); however, a concerted elimination
reaction of ( I ) with the solvent as base cannot be ruled out 171.
The reaction of the trifluoromethanesulfonate ( I ) in 50%
aqueous ethanol was characterized by a rate constant k =
9.14 x lo-4s-1 (at 75.4'C) and k = 6.03 x 10-58-1 (at
50.4'C); AH+ = 23.7 kcal/mole; AS* = 4 . 8 e.u. Thus (I)
reacts three times as fast as isopropenyl trifluoromethanesulfonate, which was solvolyzed by Stang and Summerville [Sbl
under the same conditions (k = 1.95 x 10-5 s-1 at 50°C).
Solvolysis of simple acyclic and cyclic vinyl halides and vinyl
sulfonates could proceed via vinyl cations as intermediates [I].
Received: February 13, 1970
[ Z 151 IEI
Formation of rearranged solvolysis products would indicate
German version: Angew. Chern. 82, 323 (1970)
such a reaction course.
Rearrangements of vinyl cations generated by protonation of
[*I Dr. A. Garcia Martinez
alkynes are known [Zl; in contrast, occurrence of isomeriza(Max-Planck-Gesellschaft Fellow) and
Prof. Dr. M. Hanack
tions of this kind during the solvolysis of simple acyclic vinyl
Chemisches Institut der Universitat
derivatives has not hitherto been described 131.
74 Tiibingen, Wilhelmstrasse 33 (Germany)
For the generation of vinyl cations by solvolysis of vinyl
R . H. Summerville
sulfonates the fast-reacting trifluoromethanesulfonates~~~
(National Science Foundation Predoctorial Fellow,
prove particularly suitable[sl. We now report o n the solvol1969/1970) and
ysis of I-tert-butylvinyl trifluoromethanesulfonate ( I ) which
Prof. Dr. P. v. R. Schleyer
gives rise t o rearranged products.
Department of Chemistry, Princeton University
Princeton, N.J. 08540 (USA)
Compound ( I ) was prepared by slow dropwise addition of
trifluorometbanesulfonic acid 161 at -20 "C t o 3,3-dimethylProf. Dr. P. Stang
Department of Chemistry, University of Utah
I-butyne ( 4 ) . After 30 min the reaction mixture was neutralSalt Lake City, Utah 84112 (USA)
ized by addition of a solution of N a H C 0 3 and extracted with
[**I This work was supported by the Deutsche Forschungsgeether. The extract was dried, and after evaporation of the
meinschaft, the Fonds der Chemischen Industrie, and the
ether, compound ( I ) could be isolated by distillation [yield
Petroleum Research Fund administered by the American
40-60%, b.p. 45-50°C/15 torr; N M R spectrum: T = 4.95
Chemical Society.
(2H/q, J = 4 Hz); 8.80 (9H/s)]. ( I ) was found to be homo[l] For a review, see M. Hanack, Accounts chem. Res., in
geneous o n gas chromatography (3 m polyethylene glycol
press.
20000, lo%, column, 100 "C); n o rearrangement products
[2] K . Bott, Tetrahedron Letters 1969, 1747; K. Griesbaum and
were formed during the addition.
2. Rehman, J. Amer. chem. SOC., in press; cf. also K. Bott,
Compound ( I ) was solvolyzed in pyridine-buffered 80 %
Chem. Commun. 1969, 1349.
aqueous ethanol for three days at 80 "C. There were formed:
[3] Rearrangement of a cyclopropylvinyl cation during silver27% of 3,3-dimethyl-l-butyne ( 4 ) ; 13 % of 2,3-dimethylsalt catalyzed acetolysis of stereoisomeric l-iodo-l-cyclopropylbutadiene ( 5 ) ; 24% of 3-ethoxy-2,3-dimethyl-l-butene(6);
I-propene has been reported by D . R. Kelsey and R. G . Berg1 % of pinacolone (7); 10% of 2,3-dimethyl-3-buten-2-01
(8);
man, J. Amer. chem. SOC.92, 228 (1970).
and 25 % of higher boiling substances (mean values from five
[4] T . M. Su, W. F. Sliwinski, and P . v. R. Schleyer, J. Amer.
chem. SOC.91, 5386 (1969).
experiments). After seoaration by gas chromatography the
products were identified, inter alia, by their N M R , IR, and
[5] a) W. M . Jones and D.D . Maness, J. Amer. chem. SOC.91,
mass spectra, and by comparison with authentic samples
4314 (1969); b) P . J. Stang and R . Summerville, ibid. 91, 4600
(1969).
(except for (6)).
302
Angew. Chem. internat. Edit.
Vol. 9 (1970) No. 4
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