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Chemistry of Metal Chlorides at High and Low Temperatures.

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The stereochemistry of the rearrangement of amine oxides to
hydroxylamine derivatives (Meisenheimer rearrangement)
was also investigated. Here, the isomerization of optically
active a-deutero benzyl N,N-dimethylamine oxide (2) to
optically active 0%-dcutero benzyl-N,N-dimethylhydroxylamine (3) proved a suitable object for study. Compound (2)
was obtained from the amine (5), prepared by Streitwieser
[I] from optically active a-deutero benzyl alcohol (4). Compound (3) can be decomposed to give (4) without attack at
the asymmetric centre.
-
1)
1 1 q
lalo
14 I
lldP'$
I)
I)
c6115-
12)
c-pIrs),
B
A C!slb-
I
C:~o-N(ClIs)2
I
11
(3)
Optical comparison of the original and recovered (4) showed
that about 80% of the optical activity was lost. The optical
rotations were measured with a photoelectric polarimeter
(mean error& 0.003 O). The deuterium atom is not exchanged
for hydrogen during this cycle. These results favor a twostage mechanism for the amine oxide rearrangement.
portion which consists of i>-fucoseand D-digitalose, and an
aglycone portion which is derived from a-phenylnaphthalene
or 2.3-benzofluorene. Experiments were reported that had
led to the derivation of formula (1) for the aglycone of
chartreusin [3]. The structures of some degradation products
were supported by their NMR spectra. Since then, a series
of products arising from vigorous catalytic hydrogenation of
(1) [2] have been elucidated [(4)-(7)]. The reduction of a
lactone group and the formation of an isocoumarin (6) are
worthy of note.
It was demonstrated by degradation that the disaccharide
portion of the antibiotic is attached through the 8-hydroxyl
group of the aglycone. Thus, partial hydrolysis of the phenolic
0-methyl ether of chartmusin gave (3), and oxidation with
periodic acid (uptake 1 HIO4) followed by hydrolysis caused
the appearance of methylglyoxal. From these experiments,
from the observation that chartreusin methyl ether forms an
acetonyl derivative, and on the basis of kinetic and immunochemical arguments which favor a pyranoid structure. for the
digitaloside portion, the constitution of chartreusin itself is
deduced to be (2). With the aid of the isorotation rules and
NMR spectra, the stereochemistry of both the anomeric
[GDCh-Ortsverband Marburg/Lahn (Germany),
November 9th, 19621
[VB 667/66 IE]
Chemistry of Metal Chlorides at High
and Low Temperatures
0 1I
Werner Fischer, Hannover (Germany)
Under certain conditions, the solubility of oxides in molten
chlorides can be determined quite reliably, provided that the
loss in weight which a sample of oxide undergoes during
immersion in the chloride melt for a limited time can be
measured. In CaCIZ at looO°C, 0.07% by weight of MgO
is dissolved. On adding small quantities of MgClz or CaO
to the CaCIz, less MgO is dissolved. Within the limits of
error the law of mass action is fulfilled:
[Mg*+]
[OZ-] = 340 (@molc/g)2at 1000°C (I. Cleisberg)
In molten CaC12 at 1100 "C, less than 0.001 % SiOz is dissolved(H.Fauth).At 900-1100'C,in thepresenceofO.5-8.4%
by weight ofCaO, CaC12 will dissolve cristobaliteuntil a molar
ratio of Ca0:SiOz = 3:2 is reached but no further. Apparently,
Si2Oq-ions are present in these melts, but no anions of
higher silicic acids and no SiO:-ions can exist (J. Gleisberg).
While the solubilities of individual rare earth chlorides in
water at 0 OC differ from each other by only a few per cent,
they decrease in the series from Lac13 to ErCl3 in conc.
hydrochloric acid at 0 "C by about two orders of magnitude
(H.Rohrer, J. Nier, T.Molaug, I. Dillo, and K. Dovaag).
[GDCh-Ortsverband Aachen (Germany),
November 23rd, 19621
[VB 665/67 1E]
Chartreusin
Huns Schmid, Zurich (Switzerland)
According to Sternbach, Kaiser, and Goldberg [2],chartreusin
(antibiotic X-465 A), C32H32014, which has been isolated
from various strains of Streptomyccs and which only shows
antibiotic activity in vitro, is a glycoside with a disaccharide
[I] Thanks are due to Prof. A. Streitwieser, for valuable advice.
[2] L. H. Sternbach, S. Kaiser, and M. W. Goldberg, J. eAmer.
chem. SOC. 80, 1639 (1958).
162
centres of the two sugars were also derived; as a result of
the anisotropic effect of the large aromatic aglycone portion,
the NMR signals of the two relevant protons appear at
abnormally small field strengths. Finally, it was shown that
the aglycone of chartmusin (I) is biosynthetized entirely
from acetic acid residues: the carbon atoms designated by
arise from the cdrboxyl groups, the others from the methyl
groups of ten acetic acid residues.
[GDCh-Ortsverband Freiburg/Br. (Germany),
December 7th, 19621
[VB673/69 IE]
-__ _.. -- --
[3] E. Simonitsch, W.Eisenhuth. 0. A. Stamm, and €
Schmid,
I
.
Helv. chim. Acta 43,58 (1960).
Angew. Chenr. intcrnrit. Edit. 1 Vol. 2 (1963) I No. 3
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