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Facile Synthesis of - and -O-Glycosyl Imidates; Preparation of Glycosides and Disaccharides.

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141 G. Henrici-Olive, S. Olive, J. Catal. 60, 481 (1979); R. J. Madon, ibid. 60, 485
(1979): P. A . Jacobs, H. H. Nijs, J. J. Verdonck, J. B. Uylterhoeven, Preprints,
Symposia Anaheim, CA 23, 469, ACS Div. Petrol. Chem.; H. Kolbel, D.
Schneidt, Erdol, Kohle, Erdgas, Petrochem. 30, 139 (1977).
[Sl B. Cleveland. C. R. Guamieri, J. C. Walker, Bull. Am. Phys. SOC. 15, 108
(1970).
(61 H. Schafer-Stahl, Chem.-Ing-Tech., in press.
(71 Increasing temperature, synthesis gas composition 2H,/CO (30 bar). For
comparison: Fischer-Tropsch catalysts based on graphite intercalation compounds reduced with potassium at 300 "C are catalytically active only above
300°C; M. fchikawa, M . Sudo, M . Soma, T. Onishi, K . Tamaru. J. Am.
Chem. SOC.91, 1538 (1969); V. J. Mashinskir, K A . Postinikov, Yu. N . Novikov. A. L. Lapidus, M. E. Vol'pin, Yo T. Eidus, Izv. Akad. Nauk SSSR, Ser.
Khim. 1976, 2018; S. Parkash, S. K . Chakrabartfy,J. G. Hooley, Carbon 15,
307 (1977).
[Sl J. A. Amelse, J B. Burt, L. H. Schwarlr, J. Phys. Chem. 82, 558 (1978); G. B.
Raupp, W. N Delgass, J. Catal. 58, 337, 348, 361 (1979).
191 J. S. Bradley. G. B Ansell, E W. Hill, J. Am. Chem. SOC.101. 7417 (1979).
Facile Synthesis of a-and P-0-Glycosyl Imidates;
Preparation of Glycosides and Disaccharides'"]
Aryl'
HA+ Aryl'
(zk R
= Bn,
(3): R = Bn,
(4): R = Bn,
f S k R = Bn,
Aryl'
Aryl'
Aryl'
Aryl'
= CsH5, Aryl' = p-CH3-CSH4
= Aryl' = CsH5
(6): R = Bn
f7): R = Ac
= Aryl' = p-C1-C,H4
= C,H5, Aryl' = p-(CH,)$-C,H,
By Richard R. Schmidt and Josef Michell']
Glycosides and saccharides are largely synthesized via haloses and their activation by heavy metal salts-especially
silver saltsI'-21.The disadvantages of this method are self-evident. Simplification of this approach should come from the
synthesis of sterically pure, readily isolable intermediates
with other leaving groups not requiring activation by heavy
metal s a l t ~ l ~Suitable
.~'.
candidates would seem to be, e. g., aand p-glycosyl imidates, since @-glycosyl imidates-prepared from a-haloses with silver salts-undergo acid-catalyzed reaction to give good chemical and stereochemical
yields of a-glycosides and a-~accharides~~~.
Thus a facile synthesis of a- and p-glycosyl imidates is called for''].
Ketenimines and nitriles containing electron-withdrawing
substituents are known to afford imidates directly on reaction with alcohols[61.We shall now demonstrate for the case
of the C-I -unprotected glucopyranose (1) that this reaction
can be applied to cyclic hemiacetals. Use of sodium hydride
as base and aryl-substituted ketenimines gave exclusively the
p-imidates (2)-(5) whereas the same reaction both with
benzyl- and with acetyl-protected glucopyranose ( I ) and
trichloroacetonitrile led diastereospecifically to the a-imidates (6) and (7) (Table 1). Both the 8-imidates and the aimidates, now prepared for the first time, could be conveniently isolated.
RO
"RO O
D
6R
OR
(&1j-(8e),
(a): R'
[hj:
(8h): R = Bn
= -CO-CH,
'
( 9 ~ ) - ( 9 h ) :R = Bn
( 9 1 ) - ( 9 k ) : R = Ac
(f):R' =
R' = p-CGH4-CH3
(c): R' =
( d ) : R' =
OBn
(h): R' =
H3C CH3
Table 1. 0-Glycosyl imidates (2)-(7)
(e): R1 =
prepared [a]
O
(2)
(3)
(41
(5)
(6)
84
83
93
38
96
6.11
6.11
6.05
6.1 1
6.56
5.22
5.22
5.04
5.30
8.60
7.0
7.0
7.2
7.5
3.5
(7)
85
6.60
8.77
3.5
+
+
+
1670
1650
1670
1670
1670
(Y~H:
+
+
33.0
33.0
34.5
68.7
61.5
Q
(i): R' = C & ,
2.0
1.75
1.88
1.6
1.0
3320)
1680
t103.0
1.2
( Y ~ H 3330)
:
(YCO:
1755)
[a] Abbreviations: Ac= acetyl; Bn= benzyl. All compounds gave correct elemental analyses. [h] Isolated yields. [c] 80 MHz spectra in CDCI, with tetramethylsilane as internal standard; 6 values, coupling constants in Hz. [d] [cm - 'I, film between NaCl plates. [el In CHCI,.
['I
Prof. Dr. R. R.Schmidt, DipLChem. J. Michel
Fakultat fur Chemie der Universitat
Postfach 5 5 60, D-7750 Konstanz (Germany)
["I This work was supported by the Deutsche Forschungsgemeinschaft and the
Fonds der Chemischen Industrie.
Angew Chem Inr. Ed. Engl. 19 (1980) No 9
As expected, the beruyl-protected p-imidates (2)- (5) undergo acid-catalyzed reaction with hydroxy components in
dichloromethane to form mainly or exclusively the a-linkage
product (8) while the a-imidate (6) correspondingly affords
the @-linkageproduct (9) (see Table 2). The use of carboxylic
acids [- @a), (SJ)], p-cresol [-+(8b)],steroid alcohols [ + (ad),
(9d); (8e), (9e)], and carbohydrates [-(8c), (9c); (9g); (8h),
(9h)l demonstrates the considerable scope of this simple
method of glycosidation; however, the stereochemical result
has not yet been optimized in all cases. The particularly
readily accessible acetyl-protected a-imidate (7) reacts on ca-
0 Verlag Chemre, GmbH, 6940 Wernherm, 1980
0570-0833/80/0909-0731
$02.50/0
731
Table 2. Reactants, reaction conditions, and products of glycoside and disaccharide synthesis. Dichloromethane as solvent [a]
Reactant
Cat.
(4
-
(2)
(41
Ratio
[Reactant] :[HO-R']. [Cat.]
Conditions
T
r
Yield
(8)+ (9j
I"C1
[hf
(%I P I
20
20
20
6
6
18
87
83
58
> 19: 1 [dl
TsOH
TsOH
I .4 1.2:l:l
1.4: 1 : 1
(5)
TsOH
1.5:l:l
20
96
84
3.1
(5)
TsOH
1.3: 1.1
20
96
76
5:l
(6)
(6)
(6)
-
1
BF,.Et20
TsOH
1.3:1:1.3
1.1 : 1 :0.2
20
-20
20
4
2
96
66
90
66
(7)
(7)
(71
BF,.Et,O
BF,.Et,O
BF,-Et,O
:1 -
1 :1:2.4
1 :1:0.25
1 :1:1
20
20
20
24
1
1.5
5.1
3.1
c 1.19 [d]
< I : 19 [dl
1.2
c 1 : 19 [d]
c 1 :19 [d]
< 1.19 [d]
75
58
44
Physical data of products
'H-NMR [c]
m. p.
H- 1
Jrz
["CI
[a]::,
(Raj [el
(8b)
(8c)
19d
( 8 4 [el
( 9 4 lel
(8ej
(9e)
6.36 (d)
5.43 (d)
4.86 (d)
[gl
lgl
[PI
5.02 (d)
4.45 (d)
__
3.5
7.5
(98 [el:
(9g) Iel
(8hl
(9hi
5.63 (d)
7.0
kl
(9i) [el
(9j) [el
(9kj
[g]
4.61 [d]
[g]
(8j : (9j
3.5
3.5
3.5
kl
[gl
7.5
Oil
oil
oil
140-142
102-103
oil
oil
c
[dl
+
63.7
+21.0
- 16.3
+ 47.3
+ 0.6
+126.0
+ 98.2
1.5 [ f J
1.3
1.0
1.5
1.6
1.15
1.0
oil
133-134
oil
oil
+
+
-
9.2
17.9
29.0
- 7.4
1.5
1.0
1.52
1.7
123-125
115-117
61-64 [h]
- 24.0
-18.8
+ 3.6
1.0
1.0
1.1
[a] Abbreviations: Bn = benzyl, TsOH =p-toluenesulfonic acid. All compounds gave correct elemental analyses. [b] Isolated yields based on the limiting reactant. [c] 80
MHz spectra in CDCL with tetramethylsilane as internal standard; 6 values, multiplicity in parentheses; H-l of the glucopyranosyl group, coupling constants in Hz. [d]
Only (Ra), (97). (Sg), (9i), (9jj. (9k) could be detected by chromatography; detection limit < 1 : 19. [el The data of compounds reported in the literature are in agreement with
those given; @a): P. W. Austin. E E. Hardy, J. G. Buchanan, J. Baddiley, J. Chem. SOC.1964, 2128; (8d). (9dj: G. Wuvj U. Schroder, J. Wichelhaus, Carbohydr. Res. 72, 280
(1979); (9n: J. Michel, Diplomarbeit, Universitat Konstanz 1978 (9g): see [3]; (9ijr I. Karasawa, R. Onishi, Nippon Nogei Kagaku Kaishi, 35 (8), 707 (1971), Chem. Abstr.
63, 5729e (196% (9j): T. Ogawa, K. Katano, M. Matsui, Carbohydr. Res. 70, 37 (1979). [q Rotation of the 5: t mixture. [g] Cannot be determined from the 'H-NMR spectrum. [h] Amorphous product
talysis by boron trifluoride-ether to give exclusively the pglycosides and 0-disaccharides (Pi)-(Pk). Thus a facile
method is now also available for the synthesis of p-glucopyranosides.
N-SulfinylnonafluorobutanesulfonamideA Supernucleophile['*l
By Reinhard Bussas and Giinter Kresze"'
A few years ago we had found that sulfinyl-p-toluenesulfonamide (2) is a very reactive enophile[']. In the meantime
Procedure
(2)-(7): Ketenimine (10 mmol) and sodium hydride (0.10.2 mol), or trichloroacetonitrile (3.5 ml) and sodium hydride
(10 mmol), are added to a solution of (1) (10 mmol) in dichloromethane (50 m]) at room temperature. After some time
[(2), 35 h; (3), 24 h (4), 5 h; (S), 3 d; (6), 2 h; (71, 20 min] the
mixture is filtered, concentrated, and filtered over a short
column [(2)-(S), basic alumina (activity grade I), eluant, dichloromethane/ether 1 :1; (6), silica gel, light petroleum (low
boiling)/ether 3 : 2 ; (7), silica gel, ether]. Compound (5) i s
also purified by column chromatography on silica gel (light
petroleum (low boiling)/ether= 3 :2).
Received: February 15, 1980 (2559 IE]
German version: Angew. Chem. 92, 763 (1980)
Publication delayed at authors' request
CAS Registry numbers:
( I ) (R = Bn). 38768-81-9; ( I j (R = Ac), 40437-08-9; (2j, 74808-05-2; (3), 7480806-3; (4j. 74808-07-4; (5). 74808-08-5. (6). 74808-09-6. (7). 74808-10-9 @a),
56822-49-2; (Sb), 74808-1 1-0; (Rc), 74808-12.1; (84, 41736-89-4; (Re), 74808-132; (8h). 74824-34-3; ( 9 ~ )74808-14-3;
.
(9d). 70753-59-2; (Ye). 74824-28-5: (98,
74808-15-4; (9gj. 56632-57-6; (9hj. 74808-16-5; (9i), 4468-72-8; (9y), 34382-09-7;
(Yk), 74808-17-6
Ill G. Wuw, G. Rohle, Angew. Chem. 86, 173 (1974); Angew. Chem. Int. Ed
Engl. 13. 157 (1974).
[2] Disaccharide formation by 1 -0-alkylation. which requires neither haloses
nor heavy metal salts, is fundamentally different: R. R. Schmidf, M . Reichrarh, Angew. Chem. 91, 497 (1979). Angew. Chem. Int. Ed. Engl. 18, 466
(1979).
131 See also S. Shoda, T. Mukaiyama, Chem. Lett. 1979. 847
[41 J. R. Pougny, J:C. Jaquiner, M. Nassr, M. L. Milar, P. Sinay, J. Am. Chem.
SOC.99, 6762 (1977).
[5] J. Michel, investigations for doctoral thesis.
161 D. G. Neilson in S. Patai- The Chemistry of Amidines and Imidates. Wiley,
London 1975. p. 385
732
733/ 736 Adverlisement
0 Verlag Chemie, GmbH, 6940 Weinheim. I980
II
R2.
c
I
Table 1. Comparlson of the 'H-NMR spectroscopically determined half-lives
(T,,~)[a] in the ene-reaction ofalkenes (la-g) with N-sulfinylnonafluorobutanesulfonamide (3) and with N-sulfinyl-p-toluenesulfonamide(2).
7112
(1)
(4
(bi
(Cj
(d)
(e)
Y
(g)
R'
R4
R2
-(CHd-(CH2)4-(CH2)5CI
H
H
H
i
H
H
H
CH,OCOCH,
H
H
H
H
H
H
H
R'
H
H
H
CH,
CI
B
r
H
[minl
R'
131
(2)
H
H
I
1
H
1
H
H
H
H
5
5
5
600
600
600
D6000
12000
12000
15000
1
[a] In each case determined in a 3~ CDCI, solution of I t ) and (3j or (2) at
20 "C
['I Prof. Dr. G. Kresze, DipLChem. R. Bussas
Organisch-chemisches Institut der Technischen Universitat Munchen
Lichtenbergstr. 4. D-8046 Garching (Germany)
['*I Reactions of N-Sulfinyl Compounds, Part 13. This work was supported by
the Fonds der Chemischen Industrie. We thank Bayer AG, Leverkusen, for
supplying us with nonafluorobutanesulfonylfluoride.-Part 12: [4].
0570-0833/80/0909-0732 $02.50/0
Angew. Chem. Inr. Ed. Engl. I9 (1980) No. 9
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