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Formation Structure and Synthetic Use of Acetophenone Acetals with 1 3-Dioxane Rings in Gluco- and Galactopyranosides.

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l l i c h y d r o g e n o l y t i c r i n g c l e a v a g e of t h e d i a s t e r e o m e r i c
Dieses Manuskript ist
zu zitieren als
Angew. Chem. Suppl.
This manuscript is
to b e cited as
Angew. Chem. Suppl.
1983,254-263
1983,254-263
2 ' - m e t h y l - b e n r y l i d e n e a c e t a l s w i t h LiA1114-A1C13/6/
showed
a h i g h d e g r e e of r e g i o - and s t e r e o s e l e c t i v i t y . T h e
3
mers g a v e o n l y t h e 4 - 0 - ( d - p h e n y l e t h y l ) c t h e r s
as the
D Veilag Chemie GmbH, D-6940 Weinhetm. 1983
0721-4227183!0303 0254 $02 5010
5
i s o m e r s a f f o r d e d t h e 6-O-(c+phenylethyl)
(15,LQ).
In
__ __
iso-
(&3,'$),
where-
derivatives
both c a s e s o n l y one of t h e t w o p o s s i b l e d i a s t c -
r e o m e r i c e t h e r s was f o r m e d , t h e c o n f i g u r a t i o n s of t h e new
F o r m a t i o n , S t r u c t u r e , a n d S n t h e t i c Use of Aceto henone
c h i r a l i t y c e n t e r s a r e under i n v e s t i g a t i o n . The a b o v e r e g i o -
A c e t a l S w i t h 1.3-Dioxane R i n g s i n Gluco- and G a l a c t o s e l e c t i v i t y is reminiscent t o t h e r e s u l t s obtained i n t h e
pyranosides
r e d u c t i o n s o f d i o x o l a n e t y p e E-and & - b e n z y l i d e n e
ace-
t a l s of c a r b o h y d r a t e s l G / .
By AndrAs LiptAk and P e t e r FugediX
10 and
Because compounds
T h e r e a r e o n l y two examples i n t h e l i t e r a t u r e c o n c e r n i n g
a r e ttie o n l y a c e t a l i s a t i o n
p r o d u c t s u n d e r e q u i l i b r i u m , and t h e i r h y d r o g e n o l y s i s w i t h
r e s u l t s in 6-ethers,
a n e w r o u t e f o r tile p r e -
t h e p r e p a r a t i o n o f 4,6-0-(2'-methyl)-benzylidene-hexopyra-
L i A l I i -A1C13
nosides/''.
p a r a t i o n of g l u c o p y r a n o s i d e s s e l e c t i v e l y u n p r o t e c t e d a t
In b o t h c a s e s mainly one o f t h e d i a s t e r e o m e r i c
a c e t a l s was formed, and an e q u a t o r i a l p h e n y l g r o u p p r o p o s e d
p o s i t i o n 4 f r e e is o p e n e d .
f o r t h e s e d e r i v a t i v e s by a n a l o g y w i t h t t i e c o r r e s p o n d i n g
General procedure f o r t h e p r e p a r a t i o n of e q u a t o r i a l
benzyl idene derivatives/'/.
R e i n v e s t i g a t i o n of t h e a c e t a l e x c h a n g e r e a c t i o n (DMF,
TsOH,
p-
RT) between a c e t o p h e n o n e d i m e t h y l a c e t a l and d i f f e r e n t
(1-3)
_ _
glucopyranoside d e r i v a t i v e s
p h e n y l , a x i a l m e t h y l i s o m e r s ( k i n e t i c p r o d u c t s ) o f 4.6-0-
(2'-methyl)benrylidene-hexopyranosides.
i s o m e r i c a c c t a l s , whereby t h e k i n e t i c p r o d u c t s ,
isolable in
(1-4,
_ _ lo-'
Glycopyranosides
r e v e a l e d f o r m a t i o n of b o t h
m o l ) were added t o a s t i r r e d
s o l u t i o n of p - t o l u e n e s u l f o n i c a c i d (20 m g ) and a c e t o p h e n o n e
d i m e t h y l a c e t a l ( 2 . 5 g , 1 . 5 ~ 1 0 - mol)
~
i n \,\-dimethyltorm-
*
O r . AndrAs LiptBk,
l r i s t i i u t e of
P.O.H.
Dr.
amide;
P e t e r Fugedi
D i o c h e m i s t r y , Kossuth L . U n i v e r s i t y ,
55, 11-4010 Uebrecen,
t h e g l y c o s i d e s d i s s o l v e d w i t h i n a f e w min uiid t h e
r e a c t i o n s were m o n i t o r e d b y t . 1 . c .
When t h e k i n e t i c p r o d u c t s
r e a c h e d t h e maximum (20-30%, 2-3 11)
Hungary
t h e r e a c t i o n s were
s t o p p e d by ttie a d d i t i o n of s o l i d Y a l l C 0 3 (50 mg).
-
y i e l d s of 20-3q!;,
254 -
-
were r e a d i l y c o n v e r t e d i n t o t h e thermo-
256
lhe reac-
-
t i o n m i x t u r e s were d i l u t e d w i t h d i c h l o r o m e t h a n e ( I 0 0 m l ) ,
d y n a m i c a l l y f a v o u r e d isomers. Under e q u i l i b r i u m c o n d i t i o n s
washed w i t h w a t e r ( 3 x 30 ml),
the l a t t e r a c c u m u l a t e e x c l u s i v e l y and can b e i s o l a t e d i n
r a t e d i n vacuo t o g i v e a m i x t u r e o f t h e k i n e t i c p r o d u c t ,
nearly quantitative yields. A galactopyranoside derivative
t h e thermodynamic p r o d u c t , and some unchanged s t a r t i n g ma-
(4)
r e a c t e d s i m i l a r l y to g i v e
8 a n d 12__
t e r i a l . T h e m i x t u r e s were s e p a r a t e d by column chromatoyrd-
C o n f i g u r a t i o n a l a s s i g n m e n t s a t t h e a c e t a l c a r b o n s were
derived from
'1,
and l 3 C c h e m i c a l s h i f t s of t h e C-2'
t u e n t s , being d i a g n o s t i c i n 2,2-disubstituted
substi-
phy u s i n g t h e s o l v e n t s y s t e m s g i v e n f o r t h e i n d i v i d u a l corn
pounds.
1,3-dioxanes.
F o r an a x i a l m e t h y l g r o u p t h e p r o t o n r e s o n a n c e s a r e o b s e r v e d
a t lower/3'
and the c o r r e s p o n d i n g m e t h y l c a r b o n r e s o n a n c e s
a t h i g h e r field/'/
than i n t h e e q u a t o r i a l methyl isomer.
The s h i e l d i n g of' t h e a x i a l s u b s t i t u e n t s (methyl o r q u a t e r n a r y c a r b o n of t h e p h e n y l r i n g ) i n t h e 13C-YMR
In
h e e x p l a i i i e d by t h e g a u c h e effect'5/.
i n g l y , tlie k i n e t i c p r o d u c t s ( 5
_- 8-)
t h e a x i d l methyl
ucts
(2-15)
(5) i s o m e r s ,
our case,
surpris-
( T a b l e 1) proved t o b e
(2)
4,6-0-(R)-(2'-methyl)ben~ylidene-oc-l)-qlucopyraiio-s i d-e
( 3 ) . U.p. 107-109° ( e t h y l a c e t a t e - c y c l o h e x a i i e , 1 : 3 ) ;
[c&
+29O
(c 0.80,
p y r i d i n e ) ; I?~ 0.36
(ethyl acethte);
-
y i e l d : 28%; r e a c t i o n t i m e / t e m p e r a t u r e :
130 min/25'.
s p e c t r a can
w h i l e t h e thermodynamic prod-
werc t h e a x i a l p h e n y l
d r i e d (\lazSO4), and evapo-
isomers.
hlethyl 4,6-0-(R)-(2'-rnethyl)benzyl
(6).
c h l o r o f o r m ) ; Kf
-
K-0-qlucopyranoside
(c 1 . 4 5 ,
L1.p.
95-96'
i d e n e - 2 , 3 - d i -0-methyl (2-hexarie);
L-1,
+6d0
0.42 (phexaiie-ethyl a c e t a t e , 6 : 4 ) ;
y i e l d ' 38%; r e a c t i o n t i m e / t e m p e r a t u r e :
150 min/2So.
? h i s is i n marked c o n t r a s t t o t h e e a r l i e r p r o p o s a l s f o r
t h i s t y p e of' c a r b o h y d r a t e a c e t a l s , b u t a g r e e s w e l l w i t h t h e
f i n d i n g o f L l ~ e l / ~ /t h a t i n a 2-phenyl-2-methyl-l,3-dioxane
\rethy1 2 , 3 - d i - 0 - b e n z y l - 4 , 6 - O - ( H ) - ( 2 ' - m e t h y l ) b e r i ~ y l i d e i i e u-D-qlucopyranoside
I
(z). M.p.
112-113°
(ethanol);
d e r i v a t i v e t h e a x i a l p h e n y l isomer is p r e f e r r e d by 2.55
(c 0 . 7 4 ,
kcal/mol.
9 5 : 5 ) ; y i e l d - 21%; r e a c t i o n t i m e / t e m p e r a t u r e :
T h e r a t i o n a l f o r t h e p r e f e r e n c e of a phenyl group
[K],
-57'
c h l o r o f o r m ) ; !?? 0 . 7 7 ( d i c h l o r o m e t h a n e - e t h y l a c e t a t e ,
-
0
3 11/50
.
t o occupy an a x i a l p o s i t i o n i s , t h a t i n t h e " p e r p e n d i c u l a r "
rotamer an a x r a l phenyl group can a v o i d unfavourable i n t e r a c t i o n s w i t h o t h e r hydrogens'3/.
LienLyl 2 , 3 - d i - 0 - b e n r y l - 4 , G - O - ( ~ ) - ( 2 ' - m e t h y l ) b e n , y l i d e i i e p-D-qalactopyranu
(c 0 . 7 7 ,
chloroform);
(S).
KF-
255
-
[A],,
-71°
0.50 ( d i c h l o r o m e t h a n e ) ; y i e l d : 28%;
r e a c t i o n time/temperature:
-
\l.p. 85O ( e t h a n o l ) ,
-
150 min/25°.
257
-
3
m
0
~
E
-1
0
i
0
m
u
TmI
3
Ph
*
m
RO
RO
OR OM5
I
3
c. ' .x -. -
K=ll
;
.
N
4
R=Me
7
R=On
+
N
N
C
.
d
"
I
-
258
-
Ph
the e q u a t o r i a l methyl,
(2)
a x i a l phenyl
i h e preparation
isomers (ttiermo-
L Ph*L
4,6-0-(2'-methyl)benrylidene-hexopyra-
dynamic p r o d u c t s ) o f
iiosides,
b u t t h e r e a c t i o n t u n e was p r o l o n g e d t o r e a c h t h e
equilibrium
BnO
-
S i m i l a r r e a c t i o n c o n d i t i o n s were used f o r
'?+a
of
CH+O
260
-
OBn OBn
.
OBn OBn
BnO
M e t h y l 4,6-0-(S)-(2'-methyl)benrylidene-1~-D-qlucopyrano-
-
side ( 9 ) .
12
8
=a
+209O
(g
M.p.
0.65,
168-170°
[*Iu
( e t h y l acetate-cyclohexane);
pyridine),
$
f
-
0.44 ( e t h y l acetate);
87%; r e a c t i o n t i m e / t e m p e r a t u r e :
yield:
6 h/25'.
Uethyl 4,6-0-(S)-(2'-methyl)ber~~ylidene-2,3-di-O-methyl-
('0).
kD'Jlucopyrform);
$
I
-
0.55
r e a c t i o n time/temperature:
CH,O-CH
P h >CH 0
-
CHI
CHzOH
HO
RU
(Lk).
OR OM-
14
6 4);
cliloro-
y i e l d : 88%;
Z l e t h y l 2,3-di-0-benty1-4,6-O-(S)-[2'-methyl)benrylider~e-
form);
RO
acetate,
5 h/25'.
Syrup; [w,],
N - D - q l u c o p y ~ ~
OR OM13
.Ph
/
[-I
+154O
D
(c 0 . 6 2 ,
Syrup;
(n-hexarte-ethyl
79:!;
Kf
-
0.70
(dichloromethane-ethyl
r e a c t i o n time/temperature:
+lOGo
( 2 0.77,
acetate,
chloro-
05:5), yield
5 h/50°.
Henry1 2 , 3 - d i - O - b e n z y 1 - 4 , 6 - 0 - ( S ~ ~ ' - m e t h y l ) b e n ~ y l i d e n e -
R=Me
15
-
R=Me
P-D-qalactopyranoside
10
R-On
(g
-
H=En
-
259
-
1.74,
chloroform);
(12).
__
-
X1.p.
0.05
68%;; r e a c t i o n t.ime/temperature:
-
118'
(ethanol);
(dichloromethane);
12 l 1 / 2 5 ~ .
261
-
[.CID
+2Io
yield:
tiydroqenolvsis o f the acetals.
This manuscript is
and $1c:13 (1.33 g) were added and the mixture was heated to
Dieses Manuskript ist
zu zitieren als
Angew. Chern. Suppl.
1983,264-270
reflux. . ~ f t e rthe disappearance o f the starting material
0 Vetlag Chemie GmbH. 0-6940 Welnheim,1983
To
d
stirred solution o f the acetals ( 5 ~ 1 0 -mol)
~
in dry
ether ( 2 0 ml) and dichloromethane (20 ml) LiAlH4 (0.38 g)
to be cited as
Angew. Chern. Suppl.
1983,264-270
0721-422718310303-0264
802.5010
the cooled solution was diluted with ether (50 ml) and
treated with ethyl acetate (5 ml) and water (3 ml).
The
crude products obtained after usual work-up were purified
Reaktionen von E-MethylencarbonsBureamlden nit Elcktropkilen:
1-Alkoxy-2-aza-allenium-Salze und rr-Acyl(nethy1en)ammonium-Salze
by columri chromatography.
Von
Methyl 2 , 3 - d i - O - m e t h y l - 4 - 0 - m e t h y l p h e n y l m e t h y l - D - D - q 1 u c o -
pyssra (12).
sf-
chlorotorm);
Prepared from
8;
syrup; [KjO +19Zo
0.30 ( d i c h l o r o m e t h a n e - a c e t o n e , 9:l);
(c 0.88,
yield:
77%; reaction time: 5 min.
Ernst-Ulrich WUrthwein", Rainer Kupfer und Claus Kaliba
Carbonsaureamide 1 kbnnen alj ambidente Nucleophile am Sauerstoff- oder
am Stickstoffatom elektrophil angegriffen werden. Alkylierungen und Protonierungen finden bevorzuqt am Sauerstoffatom statt unter Bildung Yon
Alkoxymethylenammonium- bzw. Hydroxymethylenammonium-Salzen 2- /1,2/. Die
isomeren 1-Angriffsprodukte,die sehr reaktiven N-Acylammonium-Salze3,
kbnnen unabhlngig durch Acylierung tertiarer Carbons2ureamide hergestellt
werden /3/.
\letllyl 2 , 3 - d i - 0 - b e n z y l - 4 - 0 - m e t h y l p h e n y l m e t h y l - R - O - q l u c o ~
pyrarlos-
chloroform);
(14). Obtained from z; syrup; LxIDt126' (c 0.97,
Rf 0.52 ( d i c h l o r o m e t h a n e - a c e t o n e , 9:l); yield:
-
98%; reaction time: 20 miri.
Metliyl 2 , 3 - d i - O - m e t h y ~ - O - m e t h y l p h e n y l m e t h y l - ~ - D - q l u c o -
(15). Prepared from 19; syrup; [KJ"
cliloroform); Ef 0.42 ( d i c h l o r o m e t h a n e - a c e t o n e ,
-
+140°
(c 1.36,
9:l);
yield:
pyranoslde
66%; reaction time- 40 min.
M e t l l y l 2,3-di-0-benzyl-6-0-methylphenylmethyl-U-0-qluco-
(ie).
__
pyranoside
Obtained from _l _l ; syrup,
262
-
chloroform);
Rf
- 0.85
[XI,
+So
( 5 1.20,
-3 ,
I .
Evans,
r.
9:l); yield:
\I.IF.
-J. Am_.
hl.
C. Morey,
U.
Ouxbury,
e.,
1, (1965)
A.
8. Foster, J.
M.
m.z.,
100, (1978)
A.
2.
B.
Wiberg,
6
-
W-ir haben die vom Diphenylmethanimin abgeleiteten E-Methylencarbonsdure/6/ mit Oxoniumsalzen alkyliert und mit starken SBuren
amide 82 und
protoniert. Die Alkylierunqsprodukte %,b und die Protonierungsprodukte
-~
10a,b sind stabile, hygroskopische, kristalline Verbindungen, die vollstandig charakterisiert werden konnten (Tabelle).
2202, and references
am. m.s.,
99, (1977)
Liptah, I,. Fugedi,
51, (1976)
5
-
(1979) 71.
/5/ D . G . Gorenstein,
/G/
7 /5r.
7
-
Uailey, H. C o n n o n , E. L. Eliel, K.
E,
Anqriff von z . B . Alkylierungsmitteln am Sauerstoffatom flihrt zu 1-Alkoxy~2-aza-allenium-Salzen5 oder zu I-Alkoxy-2-aza-allyl-Kationen 5; eine
Reaktion am Stickstoffatom hingegen erqibt N-Acyl(methy1en)amnonium-Salze
lbebber,
22.
therein.
Kes.,
-
2. 9.
/4/ P. 3. Garegg, U. Lindberg, I. Kvarnstrom, Carbohydr.
I
264
(1981) 2419.
/2/ \ . Llagyett, J .
Carbohydr.
e.,
Parrish, L. Long, Carbohydr.
(1967) 453; 8. C. Lipshutz,
m.,",
/3/
IV.
* Or. EU:.
WUrthwein, cand.chem. R. Kupfer, cand.chem. C. Kaliha
Institut fur Orqanische Chemie der Universitat Erlanqen-Wornberg
Henkestrasse 42, 0-8520 Erlangen.
-
70%; reaction time: 2 h.
/1/ h l .
Die strukturell verwandten N-Methylencarbonsaureamide ("N-Acylimlne")4,
deren GrundkUrper klirzlich erstmalig erzeugt und charakterislert bierden
konnte / 4 / , lassen als Produkte elektrophiler Anqriffe ebenfalls zwei
strukturell bemerkenswerte, hochreaktive Suhstanzklassen eriiarten: ein
-
(dichloromethane-acetone,
2
-
1
-
3
-
P.
2254.
*uAnasi, Carbohydr. E.,
C19, and references therein.
Received March 18, revised
December 28, 1982 / Z
-
263
-
416
s/
Die 13C-NMR-Daten der A1 kylierungsprodukte92,b belegen eindeutiq, daR
N -F.lethyleniarbonsBureamide von Oxonium-Salzen am Sauerstoffatom angeqriffen werden. in 9b z.B. findet man das Signal der CH2-Gruppe bei 73.32
ppm, also im typischen Etherbereich. Die C-C- und die C-0-Kohlenstoffsiqnale (169.67, 176.22 ppm; Zuordnung auch mit Hilfe y o n gekoppelten
13C-NMR-Spektrennicht eindeutig mUg1ich) lieqen i n dem Berelch, der fUr
Carbonsaureamide und fUr Methylenammonium-Salze typisch ist. Fur beide
Phenylgruppen findet man nur vier Signale, was mit der Cs-Symmetrie der
1 - A l k o x y - 2 - a z a - a l l e n i u n - F o r m 5. / ? / vereinbar 1st. Ein rasch invertierendes System 6 1st wegen der auch bei tiefer Temperatur (2.6. 9b: -70°C.
LOCI3, 25.15 MHz) unveranderten Spektren unwahrscheinlich. Auch die IROaten (Tabelle) sprechen for die lineare 2-Aza-alle-nium-Struktur 92.b
der Alkylierungsprodukte. Die intensiven Absorptionsbanden bei 1695 bzw.
1700 cm-' sind als Heteroal len-C=H=C-Valenzschwingungsbanden zu Interpretieren. Die guten Elektronendonoreigenschaften der Alkoxygruppen bedingen
die starke Verschiebung dieser Bande aus dem Ublichen 2-Aza-alleniumBereich (1050-1950 c m - l 1 7 1 ) zu den qemessenen niedngeren Wellenzahlen.
-
265
-
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synthetic, structure, galactopyranosid, formation, acetals, acetophenone, ring, dioxane, gluck, use
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