close

Вход

Забыли?

вход по аккаунту

?

Novel Mode of Formation of cis trans-1 5-Cyclooctadiene.

код для вставкиСкачать
0
0
@OCH3
+
As we were able to establish by 31P-NMR and by chemical
reactions, the formation of acyl chlorides from carboxylic
acids and POC13 proceeds via acyl dichlorophosphates (3).
When benzoic acid, triethylamine, and POC13 are reacted
in dichloromethane/ether at - 65"C, triethylammonium hydrochloride is precipitated. The presence of ( 3 a ) in the filtrate
is demonstrated by the 31P-NMR spectrum which remains
unchanged upon admixture of authentic ( 3 a ) .
If the solution is warmed to 6 0 T , benzoyl chloride and
benzoic anhydride are formed; addition of alkali chlorides
increases the percentage of acyl chloride. Apart from these
two compounds, tert-butyl benzoate (5) is formed in the
presence of tert-butanol at room temperature; benzoyl fluoride
is produced upon addition of sodium fluoride and catalytic
amounts of crown ether. Under these conditions, neither benzoyl chloride nor benzoic anhydride react with tert-butanol
or NaF. Leaving group in each case is the dichlorophosphate
ion, Cl,P(0)Oe.
+
R-C;
POCl,
+
K . Sasse in: Methoden der organischen Chemie (Houben-Weyl), 4th
Edit. Vol. 12/2, p. 556. Thieme, Stuttgart 1964
7%. Wieland, K . H. Shin, B. Heinke, Chem. Ber. 91, 483 (1958); N .
F . Albertson, Org. React. 12, 270 (1964).
C. Stol:er, A . Simon, Chem. Ber. 96, 288,453 ( 1 963); E. Fluck, E. Beuerle,
Z . Anorg. Allg. Chem. 411, 125 (1975); Z . Arnold, A. Holy, Collect.
Czech. Chem. Commun. 27, 2886 (1962); G. Martin, M . Marrin. Bull.
SOC.Chim. Fr. 1963, 1637.
H.Grunze, Z. Anorg. Allg. Chem. 324, 1 (1963).
Novel Mode of Formation of cis,tvans-l,5-Cyclooctadiene[**]
By Hans-Dieter Martin, Bernd Heiser, and Michael Kunze[*l
Highly strained, trans-configurated double bonds in eightmembered rings are usually generated by elimination['"], olefin
electrocyclic ring-opening["J, cycIoreversion[ld1,
or thermolysis['el. Previously, the cis,trans-isomerization of
cis-configurated double bonds has been used as photochemical
method[? We report here on photochemical and thermal fragmentations of the cyclic azo compound
which lead
in partly satisfactory yields to cis,trans-I ,5-cyclooctadiene (5).
131
AI
lCal
NEt3
R-C'<
0-C ( CH3)3 (5)
OH
CHzClz/
- 65 '\kO
0
60 "C
'
/
/
*
lGbl
0
1
llcl
//0
+ HNEt3ClQ +R X ,
C1
+N$T
R-C,
//O
F
The above evidence definitely establishes the acyl dichlorophosphates (3) as true intermediates in the acyl chloride
synthesis with P 0 C l 3; at the same time, the high acylating
potential of the mixed anhydrides (3) is demonstrated.
Procedure
Synthesis of ( 3 a ) : ( 2 ~ (9.80g,
) ~ 38.8
~ ~mmol) and benzoic
anhydride ( I ) , R=C6H5, (8.78 g, 38.8 mmol), are heated to
95 "C for 8 h, with strict exclusion of moisture. Fractional
distillation of the reaction mixture yields 1.7 g (17 %) of ( 2 a ) ,
b. p. 30"C/10-3 torr, and 11.3g (61 %) of (3 a), b. p. 77"C/10-3
torr.
Received: July 7, 1978 [Z 46 IE]
German version: Angew Chem. 90, 740 (1978)
CAS Registry numbers:
( I ) (R = C,H5),93-97-0;(Za), 13498-14-1 ;( Z b ) , 14456-60-1 ; f 3 a ) , 67598-46-3;
(3b), 67598-47-4; ( 3 c ) , 67598-48-5; ( 3 d ) , 67598-49-6; f3e). 67598-50-9;
(3f), 67598-51-0; (S), 774-65-2; f6), 611-94-9; ( 7 1 , 2553-04-0; tert-butyl
alcohol, 75-65-0
696
A detailed study of ( 1 ) was promoted by the previous
finding that (5) is a major product of the thermally induced
valence isomerization of the tricyclooctanes (2) and (3)[Ie1;
a diradicaloid ( 4 ) was postulated as product-determining
intermediate having three possible conformations ( 4 a)-(4 c)
fulfilling all the necessary geometrical requisites for stereoelectronically favorable cleavage. A consequence of this hypothesis
was the search for further suitable precursors for ( 4 ) and
thus also for (5). From the preparative standpoint the fragmentation of 7,8-diazatricyclo[4.2.2.0z~5]dec-7-ene (1 )
appeared the most suitable
As expected, irradiation of (1 ) (I,,, = 384 nm, E = 164) in
pentane does in fact afford (5) as main product. In
the yield of (5) is considerably lower (see Table 1).
On separation of the products slight losses are incurred
on account of the high sensitivity of (5). Compound (5)
was converted directly in the photolyzate with hexachlorocyclopentadiene.
Thermolysis of the tricyclic compound (2) under conditions
(A) likewise leads to (5) as a major product. Under conditions
[*] Prof. Dr. H.-D. Martin, B. Heiser, DipLChem. M. Kunze
Institut fur Organische Chemie der Universitat
Am Hubland, D-8700 Wiirzburg (Germany)
[**I Part 28 of the series "Small Rings". This work was supported by the
Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and
BASF AG.-Part 27: H . - D . Martin, R . Iden, H.J. Schiwek, Tetrahedron Lett.
1978, 3337.
Angew. Chem. Int. Ed. Engl. 17 (1978) N o . 9
Table I . Photolysis and gas-phase thermolysis (flow system) of ( I ), (2), and
( 5 ) . Conditions (A): thermolysis at 300"C/I4 torr; conditions (9):thermolysis at 290"C;34 torr.
~~
~
Educt
~~
(1)
(1)
(1)
(1)
(2)
(21
(51
(1)
~
Conditions
Product mixture %] [a]
(2)
(5)
(6)
(7)
pentane
In, acetonitrile
h ~ ether
.
hi,, acetone
(A), 37 "/, conversion
(B), 91 % conversion
(B), 58 % conversion
(B), 40 O'? conversion
22
19
Procedure
-
~~~~
Iiv,
45
17
63
9
3
53
59
18
56
17
20
42
5
and also reconcilable with the positive activation entropy
of this process[6! The supposition that ( 1 ) lies on the borderline between concerted and diradical decomp~sition[~'
is thus
confirmed.
12
13
11
11
19
14
4
4
5
2
18
11
15
63
50
88
[a] In some cases the product mixture contains small amounts of trans-1,2divinylcyclobutane and 4-vinylcyclohexene. The composition of the product
mixture was determined gas-chromatographically directly after the photolysis
or therniolysis.
(B) the thermolability of (5) and the isomerization to (7)
become strikingly manifest. Also the thermolysis of ( 5 ) itself
(conditions B) yields predominantly (7). The thermolysis of
(1 ) is worth noting. The formation of considerable amounts
of ( 5 ) expected a priori is not observed; the main product
is the cis,cis-diene ( 7 ) . This indicates that the thermal fragmen-
tation of (1) via the diradicaloid ( 4 ) to the cis,trans-diene
( 5 )-in contrast to the photochemical decomposition-takes
place only to a minor extent, and that the concerted
[o.-to,+oS]fragmentation to (7) is the dominant reaction.
This is in agreement with experiments[51 which demonstrate
the ability of the cyclobutane ring to participate in the process,
A solution of ( I ) (1.00g, 7.35mmol) in anhydrous and
olefin-free pentane (40mI) is irradiated (150W Hg high-pressure lamp, Duran) for 6 h at - 10°C. The conversion of ( 1 )
amounts to 50 %(decrease in extinction of the n--rc* transition
at 384 nm). After addition of 500mg (1.85 mmol) hexachlorocyclopentadiene, the volatile components are removed in a
water-pump vacuum and the residue is distilled at 135145"C/O.OOZ torr in a bulb-to-bulb apparatus; yield of adduct
C13H12C1,[4J 360mg (52%); 'H-NMR (60MHz, CC14):
6=1.80-2.45 (m, 8H, CH2), 2.50-2.75 (m, I H , CH), 2.752.90 (m, 1 H, CH), 5.65 (m, 2H, olefinic).
Received: June 26, 1978 [ Z 40 IE]
German version: Angew. Chem. YO, 735 (1978)
CAS Registry numbers:
(l),249-88-7;(2), 13027-75-3; ( 3 ) ,28636-10-4; (5). 5259-71-2; (61, 16177-46I; ( 7 ) , 1552-12-1 ; rrans-1,2-divinylcyclobutane,6553-48-6; 4-vinylcyclohexene, 100-40-3; adduct CI3Hi2CI6.67598-66-7
a) See e.g. J . L. Coke, M . C . Mourning, J. Am. Chem. SOC. 90, 5561
(1968); b) see e . q . A. J . Bridges, G. H . Whitham, J. Chem. Soc. Chem.
Commun. 1974, 142; c) C . 5. Reesr, A . Shaw, J. Chem. Soc. Perkin
Trans. 1 1975,2422; d) M . Jones, P. Temple, E . J . Thomas, G. H . Whitham,
ibid. 1974, 433; e) H.-D. Marrin, E. Eisenmann, Tetrahedron Lett. 1975,
661; H.-D. Martin, M . Hekman, G. Rist, H . Sauter, D . BelluS. Angew.
Chem. 89, 420 (1977); Angew. Chem. Int. Ed. Engl. 16, 406 (1977).
See r . g . J . A . Deyrup, M . Betkouski, J. Org. Chem. 37, 3561 (1972).
H . Tanida, S . Terarake, Y Hara, M . Waranabe, Tetrahedron Lett. 1969,
5341; E . L. Allred, J . C . Hinshaw, ibid. 1972, 387.
K . Ziegler, H . Sauer, L. Bruns, H . Froiriheim-Kuhlhorn, J . Schnridrr,
Justus Liebigs Ann. Chem. 5x9, 122 (1954).
J . A . Brrsoii, S. S . O h , E. W Prtrilio, P. Bickarf, Tetrahedron 30,
1639 (1974).
J . P . Synder, D. N. Harpp, J. Am. Chem. Soc. 98, 7821 (1976).
ABSTRACTS
Reactions of CF3-substituted arenes with nucleophilic reagents
have been compiled by I: Kobayashi and I. Kurnadaki. The
CF3 group attached to aromatic compounds was formerly
regarded as a very stable substituent, but it has meanwhile
been found that CF3 moieties present on quinolines, indoles,
benzofurans, and benzene derivatives can undergo numerous
reactions with nucleophiles. For instance, 2-(trifluoromethy1)-
Asymmetric syntheses are surveyed by D. Valentine, Jr., and
J . W Scott with regard to preparative utility. Only those
syntheses are considered in which the chiral molecules are
generated exclusively by chemical reagents and the enantiomeric ratio is at least 3: 1. Enamines and N-substituted imines,
olefins without heteroatoms at the double bond, and carbonyl
compounds serve as starting materials. [Asymmetric Synthesis.
Synthesis 1978, 329-356; 333 references]
[Rd 33 IE]
Angen'. Chrm I n t . Ed. Engl. 17 (1978) No. 9
indole (1) gives the product (2) in an SN1 reaction with
NaOC2H5 in ethanol. Although benzotrifluoride is not
attacked under these conditions, it can be degraded to p-aminobenzonitrile by NaNHz in ammonia after introduction of
a p-amino group. [Reactions of Aromatic Trifluoromethyl
Compounds with Nucleophilic Reagents. Acc. Chem. Res.
1I , 197-204 (1978) ; 20 references]
[Rd 31 IE]
697
Документ
Категория
Без категории
Просмотров
2
Размер файла
225 Кб
Теги
mode, formation, cyclooctadiene, novem, transp, cis
1/--страниц
Пожаловаться на содержимое документа