close

Вход

Забыли?

вход по аккаунту

?

An Optically Active Phospholene Oxide.

код для вставкиСкачать
the CND0/2 and nb-initio calculationsra1, which show
the reliability of the approximation chosen.
best of our knowledge this is the first resolution of a
chiralic phosphacyclic compound['].
Olah
In the 'H-NMR spectrum of the cation [C,H,]'
eta/.r3Jfound at room temperature one single signal
Methylene chloride solutions of ( I ) [ * ,31 (16.5 mmol in
10ml) and (t)-9-carnphorsuIfonic acid (previously dried
in vacuum over P,O, ;16.2mmol in 160ml)were thoroughly
which was split at lower temperatures. These authors
Table. Localized three-center molecular orbitals.
I
I
Atom
i
Function
i [C,H,]+
Linear combination coefficients
B,H,
B,H,, ab lriitio [8] [a]
1
~
C', B'
0.1995
0.0404
H
0.0404
0.4208
Localized
proportion (%)
0
0.3632
'
0
0.2143
96.1
[a] The linear combination coefficients of C N D O calculations refer
to orthogonalized (Lowdin) atomic orbitals and thus their absolute
values in bonding molecular orbitals aregreater than thecorresponding
coefficients in ab-initio calculations which refer to ordinary nonorthogonal atomic orbitals.
assigned the structure of a o-complex to the solvated
cation. According to our calculations the %-complex
should be more stable in the gas phase. This need not
contradict our results since 7t- and o-complexes can
differ considerably in their solvation energies and in
their interaction with the counter-ion.
Recently Helgstrand[" reported CND0/2 calculations on
the o-complex of [C,H,]'.
This author's results agree
well with ours, especially as regards bond angles and CH
distances.
Received: February 8. 1971 [ Z 415 IEJ
German version: Angew. Chem. 83.499 (1971)
[I] Part 2 of LCAO-MO Calculations on Chemical Reaction Pathways. - Part 1 : W Jakuberz and P . Schuster, Tetrahedron 27,101(1971).
[2] Cf. E. Berliner, Progr. Phys. Org. Chem. 2, 253 (1964).
[3] G . A . Olah, R . H . Schlosberg, D . P . Kelly, und G . D . Mateescu,
J. Amer. Chem. SOC.92,2546(1970).
[4] J . A . Pople, D. P . Santry, and G . A . Segal, J. Chem. Phys. 43, S 129
(1965);J. A. Pople and G . A. Segal, ibid. 43, S 136 (1965);44,3289(1966).
mixed and the solvent subsequently removed in vacuum.
The residual syrup was dissolved in 75 ml boiling benzene
and the hot solution rendered slightly turbid by addition
of 3-4ml n-heptane. By very slow and careful cooling,
approximately 4.1 g of the camphorsulfonate of ( I ) could
be obtained.
After double recrystallization from benzene with a little
n-heptane the specific rotation and melting point were
constant ([a];'= -40.3' (benzene); m.p. 103-104°C).
The difference between the UV spectrum (in cyclohexane)
of compound ( I ) (A,,, = 277 nm ; log E = 4.45) and that
of the salt (I.,,, = 281 nm ;log E = 3.03) shows that an ammonium (and no phosphonium) salt is present.
The (-)-enantiomer of ( I ) recovered by treatment with
dilute KOH was extracted with CHCI, and, after removal of
solvent, recrystaliized twice from n-heptane ([a];"= 69.4"
(0.6mol/l in benzene). The ORD curve is given in Figure 1.
\j \
-100'
\
G I
Y
jzoo
i
-100'
\
,
'
420
"
"
160
"
"
'
"
500
hlnmi-
" '
550
"
"
600
[S] P. Schuster, Theoret. Chim. Acta 19,212 (1970).
Fig. 1. O R D spectrum of (-)-3-methyl-l-@-diethylaminopheny1)-2phospholene I-oxide, (-)-(I), in anhydrous ethanol [7].
[6] M . J . S . Dewar in P. de Moyo: Molecular Rearrangements. Interscience, New York 1963,Vol. 1. Ch. 5.
[7] S.F. Boys, Rev. Modern Phys. 32, 296 (1960);J . M . Foster and
S.F. Boys, ibid. 32,300 (1960).
[8] E . Swrtkes, R . M . Stevens. W N . Lipscomb, and M.D. Newton,
J. Chem. Phys. 51,2085 (1969).
[9] E. Helgstrand, Acta Chem. Scand. 24,3687 (1970).
The similarity in constitution of ( - ) - ( l ) and racemic ( 1 )
was established from the IR, UV['. 61, and NMRr4*61
[t = 5.88ppm (vinyl H), J , , = 25 Hz] spectra and by
elemental anaIysisC21.
An Optically Active Phospholene Oxide
By G. Ostrogovich and F . Kerek"
We have been able to prepare the levorotatory form of
3-methyl-l-(p-diethylaminophenyl)-2-phospholene
I-oxide
( I ) via its salt with (+)-9-camphorsulfonic acid. To the
[*] Prof. Dr. G. Ostrogovich and Dip1.-Chem. F. Kerek
Laboratory for Organic Chemistry, Polytechnic Institute
TimiFoara (Romania)
498
Received: March 23,1971 [Z412 IEJ
German version: Angew. Chem. 83,496(1971)
[I]M . 1.Gallugher and 1. D. Jenkins In E. L. Eliel and N . L. Allznger:
Topics in Stereochemistry. Wiley, New York 1968,Vol. 3, p. 1-96.
[2] G. Ostrogovich, F . Kerek, A. Buzas, and N . Doca, Tetrahedron 25,
1875 (1969).
[3] L. Quin er al. [4] have shown that the compounds described by
us are 2-phospholenes.
[4] L . D. Quin and T P. Barket, Chem. Commun. 1967,914;L. D. Quin,
J. P . Gratz, and B. Barker, J. Org. Chem. 33,1034 (1968).
[5] V Hasserodt, K . Hunger, and F. Korre, Tetrahedron 19, 1563
(1963);H . Weitkamp and F. Korre, 2. Anal. Chem. 204,245(1964).
[6] G . Osrrogooich and F. Kerek, unpublished.
[7] We thank Prof. K . Schlogl, Vienna, for the O R D measurements.
Angew. Chem. internat. Edit. Vol. 10 (1971) No. 7
Документ
Категория
Без категории
Просмотров
1
Размер файла
114 Кб
Теги
oxide, optically, activ, phosphole
1/--страниц
Пожаловаться на содержимое документа