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Nucleophilic Attack on the 3-Phenyl-4-sulfidocyclobutenediylium-1 2-diolate Anion.

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principle, the resulting alkyl radical (6) could spontaneously
rearrange into radical (7). However, if the homologous radical
(8) is generated by decarbonylation of the corresponding
aldehyde no rearrangement takes place[*].
H3C\ /COOCzH5
HSC
,C00C2H5
H3C\
COOCzH5
C-H
I
HZ
COOCzH5
14)
151
+
/C\
I
CHz-COOCzH5
7
b
and mass spectrometry. The residue which cannot be extracted
with pentane contains still unreacted (3) in most cases.
Received: October 2, 1975 [Z 328 IE]
German version: Angew. Chem. 87.877 (1975)
[l] For a review, see W Friedrich in R. Ammon and W Dirscherl: Vitamin
B I Zund verwandte Corrinoide. Thieme, Stuttgart 1975.
[2] G. N. Schraurer, Acc. Chem. Res. I, 97 (1968); G. N. Schrauzer and
J . W Siberr, J. Am. Chem. SOC.92, 1022 (1970).
[3] H. Eggerer, P. Overath, F . Lynen, and E. R . Stadtman, J. Am. Chem.
SOC.82,2643 ( I 960).
[4] R . W Kellermeyer and H. G . Wood, Biochemistry I, 1124 (1962); E.
F. Phares, M . K Long, and S . F. Carson, Biochem. Biophys. Res. Commun. 8, 142 (1 962).
[5] R. H. Abeles and B. Zagalak, J. Biol. Chem. 241, 1245 (1966); P.
A . Frey, M . K . Essenberg, and R . H . Abeles, ibid. 242, 5369 (1967).
161 J . RPtey and D. Arigoni, Experientia 22, 783 (1966); G. J . Cardinale
and R . H. Abeles, Biochim. Biophys. Acta 132, 517 (1967).
[7] For a review, see D. G. Brown, Progr. Inorg. Chem. 18, 207 (1973).
[8] S. N. Lewis, J. J . Miller, and S . Winsrein, J. Org. Chem. 37, 1478
( 1972).
[9] P. Dowd, M. Shapiro, and K . Kang, J. Am. Chem. SOC.97,4754 (1975).
It is not clear from this publication whether it is the acrylyl or the
tetrahydropyranyloxycarbonylwhich migrates.
[lo] Prepared from diethyl methylmalonate and dibromomethane with 1 mol
of base.
[ I l l Nore added in proof' (Nov. 13, 1975): The cobalamin complex corresponding to (3) is so unstable that it decomposes in the dark at pH 7
within a few hours, affording (4) and (5).
Hz$
Nucleophilic Attack on the 3-Phenyl4sulfidocyclobutenediylium-l,24iolate Anion[**]
Regardless of the role the central cobalt atom and its trans
ligand (pyridine)play in the rearrangement of ( 3 ) , an analogy
with the coenzyme B1,dependent transformation of methylmalonyl-CoA ( 1 ) into succinyl-CoA ( 2 ) appears compelling.
Further characterization of the model reaction will show
whether the analogy can be pursued to greater depths.
After having obtained the present results, we learned that
Dowd et aLi9] have observed a similar rearrangement in a
system different from ours[' 'I.
By Arthur H. Schmidt, Walter Ried, Peter Pustoslemsek, and
Waiter Schuckmann[*]
The 4-sulfidocyclobutenediylium-I
,2-diolates (1 a) and
(1 b)"] belong to a new class['*2] of four-membered carbocycles displaying 2sc-electron delocalization, in which oxygen
and sulfur bear the negative charge in the anion. As expressed
in formula (1 ) the anion possesses electrophilic character;
it should therefore react with nucleophilic reagents.
2,2-Dietkoxycarbonylpropyl(pyridinato)cobaloxime ( 3 )
To a solution of CoCI, .6 H z 0 (1 mmol) and biacetyldioxime
(2mmol) in anhydrous ethanol (99.85 %) are added potassium
hydroxide (2 mmol) and pyridine (1 mmol), both in the form
of 1 M alcoholic solutions. After stirring for 15 min at 25 "C
the solution is purged with argon and cooled to -10°C.
Potassium hydroxide (1 mmol) and NaBH, (2 mmol) are then
added under argon in the dark, the argon replaced by hydrogen, and the mixture allowed to react for 1 h at - 10°C.
After warming to 25 "C, diethyl 2-bromomethyl-2-methylpropanedioate['"] (5 mmol) is added to the stirred reaction mixture. The black solution turns light orange. After 15 min
the solvent is removed under vacuum, the residue taken up
in dichloromethane, and filtered under nitrogen. Chromatography on silica gel with ethyl acetate as eluant affords 393 mg
(0.71 mmol) (3). (Beautiful orange-red needles from methanol/
water + one drop of pyridine.) NMR (100 MHz, CDCI,):
6=1.18t (6H); 1.30s (3H); 2.00s (2H); 2.12s (12H); 4.09
double sextet (4H); 7.32m (2H); 7.75t (IH); 8.56d (2H).
Compound (3) gave a correct elemental analysis.
Example of photochemical reaction of ( 3 )
Compound (3) (4 mg, 7.2 pmol) is dissolved in anhydrous
ethanol (1 ml) containing 1 % of acetic acid with half-an-hour's
stirring in the dark under argon. The solution is maintained
at 15-20°C during 90 minutes' irradiation with a high pressure mercury lamp (125 watt, Philips) at a distance of 8cm.
After removal of solvent under vacuum, the residue is extracted
with pentane and the extract analyzed by gas chromatography
Angrw. Chem. inrurnur. Edif. Vol. 14 (1975)
1 No. 12
Surprisingly,however, heating of (1 b) with aliphatic amines
merely affords ammonium salts such as (1 c ) , thus underlining
the pronounced acidity"] of (lb). In contrast, reaction of
equimolar solutions of (1 a) or (1 b) with primary aromatic
amines (THF; ethanol) leads to deeply colored condensation
products (2)-(5), even when the reaction is performed in
an ice-cold medium. Thus the electrophilic character of system
( 1 ) is confirmed and atom C-4 is ruled out as the point
of attack by nucleophiles. The IR spectrum of (4) (Table
1) suggests a delocalized bond system13]as a structural component of the novel class of compounds. Apart from the
expected absorptions, the 'H-NMR spectra of ( 2 ) and ( 5 )
contain the broad signal due to a single proton at low field
[*I Dr. A. H. Schmidt ['I, Prof. Dr. W. Ried, and DipLChem. P. Pustoslemsek
Institut fur Organische Chemie der Universitat
6 Frankfurt/Main, Theodor-Stern-Kai 7 (Germany)
Dr. W. Schuckmann
Institut fur Kristallographie der Universitat
6 Frankfurt/Main, Senckenberganlage 30 (Germany)
['I To whom correspondence should be addressed.
[**] Reactions with Cyclobutenediones,Part 43.-Part 42: W Ried, H. Knorr,
and U . Knorr, Chem. Ber., in press.
823
hydrogen carbonate and can be regenerated unchanged by
cautious acidification. If (2) is added to cyclohexylamine
and the ice-cold solution treated with dilute sulfuric acid
then ( 1 c ) is obtained. This suggests the intermediacy of the
salt (6) and emphasizes its ease of hydrolysis.
The action of diazomethane on (2) affords the thioether
(7). Cautious hydrolysis permits its degradation to (8)"l.
Treatment of a solution of (2) in THF with an aqueous
solution of HgC12 immediately precipitates the mercury salt
(9) which fulfils the conditions necessary for inner chelate
Table 1. Properties of 2-arylamino-4-phenyl-3-sul8docyclobutenediylium-l-olates
(2)-(5)
are available for all compounds.
[4] and of compounds (7) and (9). Satisfactory elemental analyses
'H-NMR [6, ppm]
Cpd.
Ph = CbH5
Ar
M. p. r C ]
solvent, color
IR [cm-'1 [a]
(2)
CsH5
212-215
ethanol,
red
(3)
2-Br-C6H4
(4)
4-CHs-ChHd
(5)
4-OCH3-CrjHd
178-1 80
benzene,
dark red
206
acetonitrile,
red
200-202
benzene,
red
129
ethanol,
yellow
3165-2850 br,
1780 w, 1735 s, 1705 sh,
1650 w, 1590 w
1725 s, 1700 w,
1620 s, 1570 s, 1550 m
(7)
350 (dec.)
191
-
9.9-10.3
[b]
3190-2680 br, 1720 w, 1700 s,
1620 s, br, 1585 sh, 1570 m
11.6-12.0
[b]
3060 w, 2970 w, 2820 w.
1740 s, 1655 m
7.88-7.69
6.94-7.50
3.09
(2 H, m)
(8 H, m)
(3 H, s) [c]
3180-2700 br, 1720 w, 1700 s,
1625 sh, 1610 s, br, 1570 m
3060 w,
1750 s, 1655 m, 1500 m
yellow
[a] s=strong, m=medium, w=weak, sh=shoulder, b=broad.
[b] 60 MHz, [D,]-DMSO, acidic H.
[c] 100 MHz, CDC13.
which undergoes ready exchange with D20. The mass spectrum of (2) is not very characteristic.
Since the spectroscopic data of the condensation products
were insufficient to permit a distinction between the structures
(2)-(5)
and the 2-substituted isomers, compound (3) was
subjected to X-ray structure analysis[51.The result confirmed
the structures (2)-(5) and hence C-1 as the site of nucleophilic attack on the 3-phenyl-4-sulfidocyclobutenediylium-1,2diolate anion. The molecular diagram15]of (3) reveals furthermore that the four-membered ring system is planar and that
the four substituents lie in the same plane. Accordingly, the
linkages between the four different substituents and the fourmembered ring system are formed by double bonds and partial
double bonds.
Compounds ( 2 ) - - ( S ) are characterized by their high acidity. They are readily soluble in a 10% solution of sodium
formation between the lone pairs of the nitrogen and the
mercury atom. Hydrolysis of (2) with concentrated hydrochloric acid leads to (I b) (see Table 1 for properties of the
new compounds).
Received: September 12, 1975;
revised: October 15, 1975 [Z 329 IE]
German version: Angew. Chem. 87.879 (1975)
A. H . Schrnidt, W R i a l , P. Pustoslmmsek, and H . Dietschmarin, Angew.
Chem. 84, 110 (1972); Angew. Chem. internat. Edit. 1 1 , 142 (1972).
a ) D. Coircoucanis, F. Hollander, R . West, and D. Eggerding, J . Am.
Chem. SOC.96, 3006 (1974); b) G. Seit;, H . Morck, K . Mann, and R .
Schriiiedelel, Chem.-Ztg. 98. 459 (1974): c) G. Seitz. K . Mormn. R. Sc/mrimiedel.
and R. Marusch, ibid. 99, 90 (1975).
W Ried, A. H . Schmidt, G. Iserihrirck, and F. B a t i , Chem. Ber. 105,
325 ( 1972).
Of the three resonance formulas of compounds ( 2 ) - ( 5 ) we employ
the central one for purposes of description and designation.
W Schirckmann. P. Pirstoslerimsek, W Ried, and A. H . Schrnirlr, to be
published.
Simple Synthesis of 1-Halobicyclooctanes~**l
[***I
f2) + CHzNa
- phmsCH3
PhwsCH3
+
HCI
'Ph
824
By Wolfgang Kraus and Hans-Dieter GrafI'[
Dedicated to Professor Eugen Muller on the occasion of his
70th birthday
We have found that 1-halobicycloalkanes are formed in
very good yield from corresponding bridgehead tosylates on
[*] Prof. Dr. W. Kraus and Dr. H.-D. Graf
Chemisches Institut der Universitat Tiibingen
Present address:
Lehrstuhl fur Organische Chemie der Universitat Hohenheim
7 Stuttgart 70, Emil-Wolff-Strasse 14 (Germany)
[*'I Part of Doctoral Dissertation of H . - D . Graif. Universitat Tiibingen 1975.
[***] This work was supported by the Fonds der Chemischen Industrie.
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