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New Ring Transformation of Zwitterionic Bicyclic Thiazole Systems.

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solvolysis of (6)-dinitroben~oate[~],
m. p. 9 4 T , in the same
medium for 3 h at 70°C gave a 7 :3 mixture of (6) and di-2,4,6cycloheptatrienyl ether. We suspect intermediate formation
of (I) which rearranges to 7-norbornadienyl cation and thus
with water furnishes 7-norbornadienol (see below). The facile
conversion of the latter into di-2,4,6-cycloheptatrienylether
in aqueous alkaline solution has recently been reportedc51.
bishomocyclopropenyl structure[']. Approach of the nucleophile methanol from the side of the free double bond, which
in this case bears a bromine substituent, at C-7, is characteristic
of 7-norbornadienyl cations[lc!
The driving force of the rearrangement, which overcomes
the allylic resonance in ( 4 ) , is most probably the lessening
of strain energy on ring expansion ( 4 ) - + ( 8 ) and the
pronounced stability of ( 9 ) .
Received: May 6, 1976 [Z 471 IE]
German version: Angew. Chem. 88, 508 (1976)
CAS Registry numbers:
( I ) , 59574-39-9; (2), 50399-12-7; ( 3 ) , 5291 1-87-2; (S), 59574-40-2; (5)-dinitrohenzoate, 59574-41-3; (6). 59574-42-4; (6)-dinitrohenzoate, 59574-43-5;
(7). 59574-44-6; ( J O ) , 59574-45-7; 3.5-dinitrobenzoyl chloride, 99-33-2; di2,4,6-cycloheptatrienyl ether, 16273-47-5; AgBr, 7785-23-1 : AgC104. 7783-93-9
14 I
A better insight into the rearrangement is provided by
cation ( 4 ) in a less nucleophilic medium. Dropwise addition
of a benzene solution of silver perchlorate at room temperature
to a solution of (3) in a 15 :4 : 2 mixture of ether, methanol,
and triethylamine[61 immediately precipitates silver bromide
and a 60 % yield of 4-bromo-5-methoxytricyclo[4.1 .O.O',']hept-3-ene (7) and 2-bromo-syn-7-methoxynorbornadiene
(1 0) in the ratio 88: 12 is isolated. Mixing of toluene solutions
of (3) and silver perchlorate at 20 or -70°C and subsequent addition of methanol furnishes a 60% yield of
b. p. 95-105°C (bath)/14 torr, as sole product. The stereochemistry at C-7 follows from the 1.1-Hz coupling constant
between H-7 and H-3c71. (7)C31, b.p. 44-45"C/0.04 torr, is
formed in 95 % yield from (3) with sodium methoxide in
methanol.
+ NaOCHJ
-
- NaBr
+ Ag'
(3)
r
- AgBr
Br
J
It is improbable that the rearrangement of the cation ( 4 )
is affected by silver(1) ions since they even fail to attack the
neutral species (7) under the conditions of the reaction. The
transition to the 7-norbornadiene system is most simply
explained by a 1,2 shift of one of the four peripheral bicyclobutane bonds to the adjacent cationic center. Thus ( 4 ) affords
( 8 ) , 2-bromo-7-norbornadienyl cation in one of the classical
formulations['"]. ( 9 ) corresponds to the generally accepted
494
[l] a) G. A . Olah and P . 0. R . Schleyer: Carbonium Ions. Wiley-Interscience,
New York; b) R . E. Leone, J . C . Barborak, and P . v. R . Schfeyer in
[la], Vol. 4, p. 1837 (1973); c) P . R . Story and B. C . Clark, Jr. in
[I a], Vol. 3, p. 1007 (1972).
[2] M . Christland G . Briintrup, Angew. Chem. 86, 197 (1974); Angew. Chem.
Int. Ed. Engl. 13, 208 (1974).
[3] Elemental analyses and mass and 'H-NMR spectra of all the new compounds accord with the given structures.
[4] H. Prinzbach, H . Babsch, and H. Fritz, Tetrahedron Lett. 1976, 2129.
We are indebted t o Prof. Prinzbach for the agreement reached concerning the preparation of ( I ) from (6).
[5] B. Franzus, M . L . Scheinbaum, D. L . Waters, and H . B. Bowlin, J. Am.
Chem. Soc. 98, 1241 (1976).
[6] In the absence of silver perchlorate, compound ( 3 ) is stable in this
mixture.
[7] Cf. E. I . Snyder and B. Frmi:ii.\. J. Am. Chem. Soc. 86, 1166 (1964).
New Ring Transformation of Zwitterionic Bicyclic
Thiazole Systems
By Sang-Woo Park, Walter Ried, and Walter Schuckmann"]
Dedicated to Professor Dr. R. Wegler on the occasion of his
70th birthday
The reaction of phenacyl bromide ( 2 ) with the bicyclic
zwitterionic thiazoles (I a ) and (I b ) , which result from a
three-component reaction of cyclic thioureas, mercury bis(phenylacetylide), and phenyl isothiocyanate['.'], does not
yield the bromides ( 4 ) corresponding to the iodides (3)['1;
instead ring opening and renewed cyclization affords the new
bicyclic thiazoles 2-[2-(7-benzoyl-5-phenylimino-2,3-dihydro1H-imidazor 1,2-c]thiazol-l -yl)-2-phenylvinylthio]acetophenone (1 Oa) and 2-[2-(8-benzoyl-6-phenylimino-l,2,3,4-tetrahydrothiazol0[3,4-a]pyrimidit1.1 -yl)-2-phenylvinylthio]acetophenone (fob), respectively.
Since no unequivocal structural information about products
(10) could be derived from their spectroscopic data, the molecular structure of (10a) was solved by X-ray methods. The
formula scheme shows the suspected mode of formation of
these compounds. Simultaneous formation of the salt (7)[3,41
apparently results from a secondary reaction of the unstable
primary product ( 4 ) under the action of (1 ). Direct reaction
of ( 1 ) with HBr likewise proceeds via ( 5 ) to give the salt
( 7 ) , from which the free base (9)['1 is obtained with aqueous
K 2 C 0 3 solution. The phenyl isothiocyanate isolated by
column chromatography can be trapped as N,N'-diphenylthiourea with aniline in methanol.
[*] Dr. S . W. Park and Prof. Dr. W. Ried
lnstitut fur Organische Chemie der Universitat
Theodor-Stern-Kai 7 , 6000 Frankfurt/Main 70 (Germany)
Doz. Dr. W. Schuckmann
Institut fur Kristallographie der Universitat
Senckenberganlage 30, 6000 Frankfurt/Main I (Germany)
A n y i w . Chem.
In[, Ed. Engl. J Vol. 15 (1976) N o . X
Ph-N,
with benzene/ethyl acetate 3 : 1) furnishes (10). Recrystallization from a little acetone in the cold gives yellow crystals.
cA - C H 3
Received: May 5, 1976 [Z 472 IE]
German version: Angew. Chem. 88, 51 I (1976)
n
r
l
CAS Registry numbers:
(/n),55139-32-7: f/h),55139-34-9:
(I), 70-11-1; ( 1 0 0 ) . 59643-55-9; ( / O h ) ,
59643-56-0
W R i d . R . Oueiiius, and W M u r k e l , Angew. Chem. 84. 535 (1972);
Angew. Chem. Int. Ed. Engl. I ! , 511 (1972).
[2] M! R i d , W M e r k e l , S . W Pork, and M . Drugei', Justus Liebigs Ann.
Chem. IY75, 79.
[3] M! Wilsoii and R. W'odgrr, J . Chem. SOC. 19.55, 2943; M. Frfbr and
L . C. King. J. Org. Chem. 26. 828 (1961).
[4] I/ K . C h d h ~
and H . K . Pujori. Can. J . Chsm. 4 7 , 2843 (1969).
[I]
Ph-NPC ,a-H
(51
- 1 ' 1 ~ N=C=S
Complete Asymmetric Synthesis and Absolute Configuration of an Aminoacylmolybdenum Complex
1
r
By Woljqang Beck, Wolfqmg Dunzer, Anh Tliu Liu, and Gottfried Huttner[*]
Previously described reactions of q 5-cyclopentadienyltricarbony1 hydrides of molybdenum ( I ) and tungsten with substituted aziridines ( 2 ) [ ' l suggested that the P-aminoacyl chelate
complexes ( 3 ) are formed with asymmetric induction.
I
(I,
CI
h
c
d
PhnH
f2
/
Table I . Data for compounds ( 1 0 1 1 ) and ( / O h ) (correct elemental analyses
and mass spectra are available).
~~~~~~
-
~
Yield
M.p.
[":I
I"c1
IR [a!
[cm-
R3
Me
Me
H
H
H
r-Bu
Ph
Ph
H
Ph
H
H
Me
Me
Me
H
Et
H
(/(JO)
40
I97
3060
I680
(/Oh)
32
I54
3060
I690
~
(-)578
(
+ 157s
(+)S78
[dl
[bl
-687"
+ 100"
r.1
+
51.3"
[a] cis-(2R,3S); [b] rran.+(ZS,3S); [c] ( 3 R ) ; [d] in acetone
~~
' H - N M R [b]
1
[a. Ppml
-~
~~
~~~~~
R2
\S-CHZ-C-Ph
n = 2
b , n = 3
~~
R'
~~
3 . 8 6 4 . 2 ( m ; 6H)
6.06 (5: 1 H)
6.68-7.96 (m: 2OH)
1.5~-2.1 (m: 2H)
3 . 1 4 . 2 ( m ; 6H)
5.94 (s; I H )
6.7-X.1 (m: 2OH)
-
I ~ = C H )and v(C=O) in KBr.
[b] Conditions: 100 MHz.CDCI,. hexamethyldisiloxaneas internal standard.
[d]
General procedure:
A solution of ( 2 ) (2mmol) in acetone (10ml) is added
to a solution of ( 1 a ) in hot acetone (200ml; iOOml in the
case of ( 1 b ) ) . After refluxing for 5 min and standing at room
temperature for several hours the colorless crystals of (7)
are filtered off and the solvent distilled from the filtrate in
a rotary evaporator. After addition of a little chloroform
and keeping at room temperature the residue is freed from
insoluble components and once again evaporated to dryness.
Column chromatography of the residue on silica gel (elution
By reaction of ( I ) with the optically active aziridines ( 2 a )
and ( 2 h ) and X-ray structure analysis of the complex ( 3 a )
we found that complete asymmetric induction occurs at two
prochiral centers in a specificity-determining step. IR spectra
show that the aziridine ( 2 ) is initially protonated and then
undergoes nucleophilic attack at C-2 by the carbonylmetalate
ion. Ring opening is regiospecific; in ( 2 c ) the Mo atom is
bonded to the unsubstituted C atom, and in ( 2 d ) to the
phenyl-substituted one.
Reaction of ( 2 f ) affords the aminoalkyl complex (4.f). The
intermediacy of the complexes ( 4 a ) to ( 4 e ) also follows
from the fact that the compound (5c)c31, obtained according to
Knotli[2],can be converted into the chelate complex (3 c).
Crucial steps for the stereospecific formation of ( 3 ~from
)
( 4 a ) are the "CO insertion" and the coordination of the
I'[
Prof. Dr. W. Beck, Dipl.-Chem. W. Danzer, and Dipl.-Chem. A. Liu
lnstitut fur Anorganische Chemie der Universitit
Meiserstrasse 1. 8000 Miinchen 2 (Germany)
Doz. Dr. G. Huttner
Anorganisch-chemisches Labordtorium. Fachbereich Chemie der
Technischen Universitiit
Arcisstrasse 21. 8OOO Munchen 2 (Germany)
495
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transformation, zwitterion, bicyclic, ring, system, thiazol, new
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