close

Вход

Забыли?

вход по аккаунту

?

Mixed SiloxaneSilazane Compounds.

код для вставкиСкачать
octatetraene added photochemically occurs in I1 as a bicyclo[4,2,0]octa-1,3-diene and in 111 as a cycloocta-l,3,5triene unit. If irradiated in the presence of Fe(CO)5, both 11
and 111lose benzene, and a new yellow-red binuclear complex
(IV) of formula CloHloFez(CO)6 and m. p. 17OoC (decomposition) is formed.
Received, May 21st. 1962
[Z 288/119 JE]
Structure of the Main Component
of Gamboge Resin
By Prof. Dr. H. Auterhoff, H. Fraudendorf,
W. Liesenklas, and Dr. C. Schwandt
Institut fur Pharmazeutische Chemie
dzr Technischen Hochschule Braunschweig (Germany)
[ I ] Compound (1) has also been described by A. Davison et al.,
Chem. and Ind. 820 (1962).
121 Performed in Jena glass vessels, using a 200 watt mercury
vapour lamp as light source.
[3] Irradiation for shorter periods of time results in CsHsFe(CO)3,
together with a small amount of CsHsFe2(C0)6; M . D. Rausch
and G. N. Schraurer, Chem. and Ind. 957 (1962).
Wurtz Syntheses with Naphthalene-sodium
By Dipl-Chem. H. Gusten and Prof. Dr. L. Horner
Institut fur Organische Chemie
der Universitat Mainz (Germany)
During our investigations of the possibilities of employing
naphthalene-sodium in organic syntheses [ I , 21, we used this
reagent introduced by Scott [3] virtually as "dissolved sodium". Exceptionally good results were obtained in the
Wurtz synthesis [4].
If the green solution of naphthalene-sodium, prepared in the
apparatus previously described [2], is added dropwise at
-6OOC to a solution of an aromatic halide, the drops are
immediately decolorized. The solution quickly becomes turbid owing to precipitation of sodium halide. If the reaction is
carried out under pure nitrogen in absolute tetrahydrofuran
using pure, dry starting materials, the end point can be
determined exactly by titration. In order to isolate the
reaction product, the solvent is distilled off and the naphthalene formed is removed by steam distillation. When benzyl
halides are used, the residue from the steam distillation
primarily contains the dimerization product in a very pure
state. Catalytic quantities of naphthalene may also be used;
the steam distillation can then be omitted. The yields of
crude material are better than 90%. Similar experiments
with tetraphenylethylene disodium were recently reported by
Muller and Roscheisen [5].
The reaction between naphthalene-sodium and benzyl halides
proceeds according to the following equation :
2 RCHzCl
+ 2 Na(naphtha1ene)
+ RCH2CHzR
Seventy-five per cent of gamboge resin (gummi gutti), the
dried milky exudate of Garcinia species from Southern Asia,
is an ether-soluble material, the main component of which is
P-guttilactone (sometimes called P-guttic acid). This can be
isolated as its pyridine [l] or a-picoline complex. The acidity
of the compound is due to its phenolic character. Acetyl-Fguttilactone is obtained by acetylation with acetic anhydride
in the presence of perchloric acid. If the acetylated material is
heated with 5 % ethanolic potassium. hydroxide, a phenolic
substance of formula C25H3204is obtained, and in the mother
liquor, y - b u t y r o l a c t o n e can befound IftheC2s-phenolis
heated with AICI3 to 160-170°C, a substance of empirical
formula C15H1204 is produced which is identical with synthetic 1,3-dihydroxy-2,4-dimethylxanthone(m. p. 247 "C)
and which crystallizes after methjlation in the 3-position
(m. p. 184OC). In the natural product, the hydroxyl at C-3
forms an ether linkage with geraniol. This is clearly evidenced
from identification by gas-chromatography of the following
cleavage products from the Czs-phenol:
Heating with 50 % KOH -+
2-methylhept-2-en-6-one
Heating with CH3COOH in a sealed tube
+ geranyl acetate
Hydrogenation with 1 mo!e H?/P?O>,then cleavage with 50 % KOH -+
2-methylheptan-6-one
Exhaustive hydrogenation, then cleavage with AKl3 +
3,7-dimethyloctanol
0
OOH
\:'
I
1 P-guttilactone
lactone 1
-y-butyro-
0
(I)
0
OH
OH
+ 2 NaCl +
(naphthalene).
The following compounds were used as starting materials
(the first number indicates the melting point [ "C] the second
the yield [%I: R = phenyl (51, 80); a-naphthyl (163, 71);
benzhydryl (21 1, 71); 3,4-dichlorophenyl (184, 6);9-bromofluorene (240, 64). Dichlorodiphenylmethane yields tetraphenylethylene (220, ca. 50).
As can be seen in the case of 3,4-dichlorobenzylchloride,
naphthalene-sodium does not react very selectively with
organically bound halogen. Only 6 % ofthe expected 3,3',4,4'tetrachlorodibenzyl, in addition to unknown reaction products and 50% unchanged starting material, are obtained.
The conversion of u,w-dicarboxylic esters into cyclic acyloins,
in analogy to the method of Hansley, Prelog, and StoN [6],
cannot be achieved using naphthalene-sodium. Once more
the theory is confirmed that this acyloin ring closure occurs
on the surface of metallic sodium.
Received, May 30th, 1962
[Z 299/131 IE]
[ I ] L.Horner, P.Beck, and H.Hoffman,Chem.Ber. 92,208 (1959).
[2]L. Horner and H . Gusten, Liebigs Ann. Chem. 652, 99 (1962).
[3] U.S.Patent 2027000; Chem. Abstr. 30, 1392 (1936).
[4] N. D. Scott, J . F. Walker, and V. L. Hansley, J. Amer. chem.
SOC. 58, 2442 (1936).
[ 5 ] E. Muller and G. Roscheisen, Chem. Ber. 90, 543 (1957).
[6] V . Prelog et al., Helv. chim. Acta 30, 1741 (1947).
Angew. Cheni. internat. Edit.
1 Vol. 1
(1962) 1 No. 8
CH3
C,s-xanthone
The reactions permit the structural formula (I) to be written
for P-guttilactone.
p-Guttilactone is optically active; the pyridine complex has a
specific optical rotation [a]&2 = -560" (c = 2.4 mg/ml,
methanol). In accordance with its formula, the Cnpphenol
does not rotate the plane of polarized light
Received, June 6th, 1962
[Z 301/133 IE]
(11 N. Amorosa, Ann. Chimica 45, 40 (1955); Chem. Zbl. 11378
( 1958).
Mixed SiloxanelSilazane Compounds
By Dr. Carl R. Kruger and Prof. Dr. Eugene G. Rochow
Department of Chemistry, Harvard University, Cambridge,
Massachusetts ( U S A . )
Dihalogenopolysiloxanes Cl(SiR20Jn-SiR2Cl (I) (n = 1,2,3)
react with ammonia in etheral solution to form the ring compounds 11, I U , and IV besides thermally unstable polymers
((SiR20)nSiR~NHlk.
455
I1 [ I 1
b.p.!760 mm Hg
b.p.19 mm Hg
m.p.
n$,O
sp. gravity
IV
111
206-208 "C
151-151.5 " C
82-83 "C
37 "C
9.5-10.5 "C
(sublimes readily)
1.4068
0.9895 (25 "C)
190-191 "C
-
20-20.5 "C
1.4151
0.9921 (26 "C)
oxy-estra-p-quinol-(lo@)-methyl ether (m. p. 152-154 "C,
[a]g -44 "). By using ethanol or butanol as solvent, the corresponding ethyl or butyl ethers are obtained: e.g. tetralin-pquinol ethyl ether (liquid at room temperature) or tetralin-pquinol n-butyl ether (liquid at room temperature). The reaction is strongly catalyzed by boron trifluoride, the degree
depending on the p-alkyl substituents (Table 1). Thallium triacetate generally gives lower yields than lead tetracetate. pQuinol acetates are formed only in traces. These findings are
interpreted as supporting an ionic mechanism for the oxidation.
Table 1. Yields from the reaction of p-alkylphenols with thallium
triacetate or lead tetracetate in methanol, catalyzed by boron trifluoride
Compounds 11, 111, and IV are readily soluble in non-polar
etherate. The yields are determined by the DNPH-method [2]. Limits of
solvents and can be hydrolyzed in acidic media. With soderror +: 2 %. Values in parentheses: yields without addition of BF3
amide or phenyl-lithium, fission of the Si-0 bond occurs.
With I under similar conditions, methylamine yields only
monomeric compounds of the general formula
p-Alkylphenol
(V) (n = 1, b.;.
50-51 "C/
RNH-(S~RZO)~-S~RZNHR
11 mm Hg, n g = 1.4105; n = 2, b.p. 78-79'C/11 mm Hg,
t$' = 1.4089), which do not condense thermally to form ring
p-Cresol
16
36
Ethyl p-hydroxyphenylacetate
0
compounds.
20 (2)
42 (39)
6-Tetra101
5616)
Treatment of I with sodium bis(trimethylsily1)amide [2] in
29
Estradiol- 17P-acetate
29
benzene solution in a 1 :1 molar ratio produces good yields of
R~-CI
easily hydrolyzable oils ( R $ ~ ~ ) ~ N - ( S ~ R Z O ) ~ - S ~ (VI),
[Z 312/143 IEI
Received, July 7th. 1962
e . g . n = 3, b.p. 122-125 'C/2 mm Hg, n 8 = 1.4323, which in
etheral solution with gaseous ammonia at 0°C yield silyl[ I ] E. Hecker and R . LattreN, Chern. Ber., in press.
amines,e.g. n = 3, b.p. 98-99'C/lrnmHg,n3= 1.4317,s~.
[2] E. Hecker, Chem. Ber. 92, 3198 (1959); 93,2928 (1960).
gravity = 0.9886 at 27 "C. By thermal elimination of ammonia,
these can be converted into disilazanes, e.g.
R3Si
\
,,N-(SiR*O),
-SiRZNHSiRZ-(SiRzO),-N
RgSi
PR3
Splitting
C-C Double Bonds with Sodium Hydrazide
'SIR3
VII
By Doz. Dr. Th. Kauffmann, Dip1.-Ing. H. Henkler,
Dr. C. Kosel, cand. Ing. E. Rauch, Jutta Schulz, and
Reingard Weber
(n = 3. b.p. 196-198 "C / 1 mm Hg. n$,O = 1.4437).
Partial hydrolysis of the halogensiloxanes VI in ether with
pyridine as hydrogen halide acceptor yields silanols (e. g.
q = 3, b.p. 103-104"C/1.5 mm Hg, n g = 1.4308) or disiloxanes (VIII):
RpSi
I'
1,
,,N-@~RZO)~-S~R~- 0
R3Si
VIII
( e x . n = 3 b.p. 214-215"C/ 1 mm Hg, n 8 = 1.4339, sp. gravity=
0.9905 at 26 "C).
The disiloxanes obtained are thermally stable oils; e.g. compound VIII, when n is 3, can be heated under normal pressure
almost to 400 "C without decomposition. They are readily
soluble in non-polar organic solvents, but are hydrolysed in
acidic media.
Received. Tune 7th, 1962
Institut fur Organische Chemie
der Technischen Hochschule Darmstadt (Germany)
In boiling ether under pure nitrogen, sodium hydrazide splits
the alkenes shown below at their olefinic double bond, each
yielding a nitrogen-free and a nitrogen-containing fragment.
Free hydrazine in the reaction mixture generally facilitates
the fission, but suppresses it with stilbene by promoting the
competitive reaction of reduction to dibenzyl. The nitrogen
free fragment was isolated in every instance, the yields being,
as a rule, over 80 7;.
Experimental results:
styrene [I] +toluene (3 hours, 81 %)
P-methylstyrene + toluene (8 hours, 86 %)
fi-ethylstyrene + toluene (6 hours, 83 %)
frans-stilhene -+ toluene [21 (1 hour, 32 %)
a-methylstyrene + phenylethane (6 hours, 84 %)
a-phenylstyrene + diphenylmethane (6 hours, 97 %)
p,,@-dimethylstyrene+ toluene (6 hours, 74 %).
[Z 295/128 IE]
[l] N . N . Skolow, J. Gen. Chem. U.S.S.R. 29, 258 (1959), c t
Chem. Abstr. 53, 21622 (1959).
[2] U. Wannagat and H . Niederpriim, 2. anorg. allg. Chem. 308,
357 (1961); Chem. Ber. 94, 1540 (1961).
By Priv.-Doz. Dr. E. Hecker and Dr. R. Lattrell
In the experiments with stilbene and @,@-dimethylstyrene,
in
addition to the nitrogen-free fragment, the nitrogenous fragments could also be isolated, being identified as the hydrazone
of benzaldehyde and acetone, respectively (28 % and 53 %,
respectively). In the other fission reactions, acid hydrolysis
of the nitrogenous fragment, which was not isolated [3], afforded formaldehyde (from styrene), acetaldehyde (from
Max-Planck-Institut fur Biochemie, Munchen (Germany)
GHs
Preparation of p-Quinol Ethers with Boron
Trifluoride as Catalyst
\
The ethers ofp-quinols are of considerable interest [I], yet a
general method for their preparation has been hitherto unknown. If p-alkylphenols are oxidised with lead tetracetate
or thallium triacetate in methanol, p-quinol methyl ethers are
obtained: e.g. tolu-p-quinol methyl ether (m.p. 62-63 "C),
tetralin-p-quinol methyl ether (m.p. 42-43 "C), or 17P-acet-
456
R
/
c=c
R/
\R,
1.
2.
+ NaNH--NHz/34'C 4
+ HzO
R/
Angew. Chem. internat. Edit.
'R"
Vol. I (1962) I N o . 8
Документ
Категория
Без категории
Просмотров
1
Размер файла
224 Кб
Теги
compounds, siloxanesilazane, mixed
1/--страниц
Пожаловаться на содержимое документа