close

Вход

Забыли?

вход по аккаунту

?

Functionalization at Proanomeric Centres by Photobromination. A Novel Access to Oxo- and Acyloxyimino-glycosyl Bromides

код для вставкиСкачать
ausgeethert.
D i e g e t r o c k n e t e E t h e r p h a s e w i r d i m Vakuum d e -
a b s t r a c t i o n s t e p g i v e s r i s e t o o v e r b r o m i n a t i o n and,
s t i l l ie r t .
o n l y moderate y i e l d s .
e r~a t ~ur
_L i t___-_
By p l a c e m e n t o f a n e l e c t r o n a c c e p t o r g r o u p ,
/1/ W.
0x0-
or
i m i n o f u n c t i o n a l i t i e s n e x t t o t h e proanomeric c e n t r e .
Ebertz,
Dissertation.
Rheinisch-Westfllische
Techni-
-or
C - H b o n d becomes p u s h - p u l l
sche Hochschule,
Aachen 1981.
stituted,
__
/ 2 / G . S c h m i t t . P. K l e i n , W. E b e r t z , J. Orqanomet.
-___ Chem.,
i m Druck.
/3/
i.e.
mostly,
and,
that
c a p t o d a t i v e l y 171 - sub-
hence, h i g h l y r a d i c o p h i l i c . A c c o r d i n g l y ,
r a d i c a l l y i n d u c e d r e a c t i o n s a r e e x p e c t e d [B]
t o proceed w i t h
c o n s i d e r a b l y g r e a t e r ease a t s u c h " a c t i v a t e d " p r o a n o m e r i c
I n 4 - S t e l l u n g d i s u b s t i t u i e r t e 2 - O x a z o l i n e r e a g i e r e n unc e n t r e s and,
hence,
s h o u l d b e endowed w i t h h i g h e r r e g i o - and
t e r v e r g l e i c h b a r e n Bedingungen n i c h t .
1 4 1 J.A.
/ 5 / W.
;!
Frump, Chem. Revl
Krabbe.
652;
E.
E. P o l z i n .
W e l z e l . G.
js
Abstr.
kELp$
i s amply i l l u s t r a t e d b y t h e smooth,
Chem.
B e-r . g
-______
FLLrz
Greber,
(1940)
of
1.088.279
( 1 9 6 1 ) 15353; 0.
( 1 9 6 5 ) 4523; P .
1.224.304
K u r t z . W.
Chem. __
764 ( 1 9 7 2 ) 69;
-~
Ann.
DE-PS 2.336.977
(1965),
Kurtz,
W.
Chem.
- _ _ _ -A b s t r .
65
Disselnkotter, Justus Liebigs
H. S c h n a b e l ,
shzm.
(1975),
T i s c h l e r , M.H.
A.N.
through photobromination i n t o t h e i r r e s p e c t i v e pro-
z-
Ben-Ishai,
~
( 1 9 6 6 ) 16871; P.
1- 6
h i g h y i e l d conversions
anomerically brominated d e r i v a t i v e s
R. G i g e r . T e t r a h e d r o n Lett,
Disselnkotter,
T h i s e x p e c t a t i o n p r o v e d t o be c o r r e c t as
( 1 9 7 1 ) 483.
Culemeyer,
K.
Husemann. G.
( 1 9 6 0 ) . !hem.
stereoselectivity.
Tischler.
Abstr,
M.
BE
Mitzlaff,
(1975) 1132;
p?tetihedron
Lett.
(1978)
3407.
12
[9].
The t e c h n i q u e u t i l i z e d i n v o l v e s i n t e r a c t i o n o f t h e r e s p e c t i v e
p y r a n o i d compound w i t h NBS o r b r o m i n e i n r e f l u x i n g t e t r a chloromethane and i r r a d i a t i o n w i t h b r i g h t l i g h t as g e n e r a t e d
b y a 2 5 0 U t u n g s t e n lamp o r a 450 W I R h e a t l a m p . The p r e s e n c e o f b a r i u m c a r b o n a t e as a s c a v e n g e r f o r h y d r o g e n b r o m i d e
may b e d e s i r a b l e t o p r o t e c t a c i d - s e n s i t i v e b l o c k i n g g r o u p s
a l t h o u g h n o t n e c e s s a r y . The r e a c t i o n i s i n v a r i a b l y c o m p l e t e
w i t h i n 15 ( t u n g s t e n l a m p )
E i n g e g a n q e n am 2 4 . MPrz 1 9 8 2 / Z
171 S/
-
60 rnin ( h e a t l a m p ) . C o m p a t i b l e
w i t h b r o m i n a t i o n c o n d i t i o n s a r e b e n z o y l o x y and a c e t o x y
[lo],
g r o u p s , w h i l s t m e t h o x y [6], s i l y l o x y
and,
e x p e c t e d l y 1111, g - b e n z y l i d e n e
g-isopropylidene,
functions are unsuited
f o r these purposes.
-
- 1448 -
i
1450
[l,121 and
With t h e r e a d i l y a c c e s s i b l e
This manuscriptis
to be cited as
Angew. Chem. Suppl.
1982,1449- 1459
Dieses Manuskript ist
zu zitieren als
Angew. Chem. Suppl.
1982,1449-1459
0 Verlag Chemie GmbH. D4SJ-UIWeinheim. 1982
07214Z?7/82/0808-1449802 5010
-
nation i s essentially stereospecific,
the 0-glycosyl
[a]:'
= +ljgo,
bromides
1 (cf.
2
[13] p h o t o b r o m i -
no p r o d u c t s o t h e r t h a n
E x p e r i m e n t a ) ) and 8 (amorphous,
chloroform) being detectable,
thus i s o l a t i o n
o n l y r e q u i r i n g f i l t r a t i o n o f t h e s u c c i n i m i d e f o r m e d and
removal of t h e s o l v e n t . B e i n g g l y c o s y l h a l i d e s w i t h a non-
p a r t i c i p a t i n g group n e x t t o t h e r e a c t i v e anomeric c e n t r e
F u n c t i o n a l i z a t i o n a t Proanomeric C e n t r e s by P h o t o b r o m i n a t i o n .
t h e i r u t i l i t y f o r the preparation o f
A N o v e l Access t o 0 x 0 - a n d A c y l o x y i r n i n o - g l y c o s y l
F r i e d e r W.
Lichtenthaler
B r o m i d e s [l!
and 8 - l i n k e d
g l y c o s y l - g l y c o s i d e s i s o b v i o u s [16]. Y e t , e n o l o n e s a r e a s
and Pan J a r g l i s
.OBz
The e x t e n s i v e r a n g e o f r e a c t i o n s u n d e r g o n e b y s u g a r s a t t h e
Q
OBZ
z
a n o m e r i c c e n t r e and t h e measures t o be t a k e n f o r c o n t r o l o f
t h e i r s t e r e o c h e m i s t r y form t h e backbone o f c o n v e n t i o n a l
carbohydrate chemistry 121.
1
2
I n c o n t r a s t , r e a c t i o n s o f mono-
saccharides a t t h e i r proanomeric centres,
i.e.
NBSI h;
87%
t h o s e becoming
a n o m e r i c b y i n t r o d u c t i o n o f a f u n c t i o n a l g r o u p a t C-4 i n
f u r a n o i d o r C-5 i n p y r a n o i d s y s t e m s a r e r a r e i n t h e l i t e r a ture;
Q
t h e y u s u a l l y i n v o l v e e l a b o r a t i o n o f a d o u b l e bond i n
t h e p r o a n o m e r i c p o s i t i o n and s u b s e q u e n t a d d i t i o n r e a c t i o n s
9
anomeric C-H bond b e i n g enhanced by e l e c t r o n i c a s s i s t a n c e
f r o m t h e r i n g o x y g e n 151. T h i s l a t t e r p r o c e d u r e ,
though e n t i c i n g l y s i m p l e ,
however,
i s l i m i t e d t o p e r a c y l a t e d sugars
161 and due t o r e l a t i v e l y l o w s e l e c t i v i t y i n t h e h y d r o g e n
Prof.
Ur.
F.W.
Lichtenthaler. D r .
P.
Jarglis
I n s t l t u t far Organische Chemie d e r T e c h n i s c h e n H o c h s c h u l e
Darmstadt,
PetersenstraBe 22.
D-6100
- 1449
-
0
OBZ
131 o r f r e e r a d i c a l b r o m i n a t i o n 141. h o m o l y s i s o f t h e p r o -
Daimstadt
-
1451 -
r e a d i l y a c c e s s i b l e s i n c e a l c o h o l y s i s under s l i g h t l y b a s i c
Attempts t o prepare t h e oximinoglycosyl c h l o r i d e analog of
c o n d i t i o n s i s accompanied by a - e l i m i n a t i o n o f b e n z o i c a c i d .
Accordingly,
a f f o r d s t h e 8-enolone
t h e p r e s e n c e o f NaHC03 ( 1 h r e f l u x ,
12
on m e t h a n o l y s i s i n
19
80 % ) o r t h e a-anomer
when m e t h a n o l t r e a t m e n t i s p r e c e e d e d b y i n s i t u a n o m e r i z a t i o n
w i t h t e t r a e t h y l a m m o n i u m b r o m i d e (66 % )
- both
known compounds
, 1 7~.
3
the tribenzoyl-enolone
reackily.
due t o o n l y one c o n f o r m a t i o n a l l y
left,
(a-OBz)
and,
- 163OC;
181
i s nearly planar
ive, h i g h l y stable a-glycosyl
=
lei:'
-
153
154OC,
c h l o r i d e (syrup.
[aJio =
1a1i2 =
(CI i n s t e a d o f Br,
chlorides
19-
+155O i n C H C 1 3 , 67 % ) and
+198O i n C H C 1 3 , 9 0 % ) i s e f f e c t e d ,
reactand.
determining substituent
b e i n g t h e =,a-isomer
4
or
t e t r a c h l o r o m e t h a n e (3 - 4 h ) c l e a n c o n v e r s i o n t o t h e r e s p e c t -
Acknouledgernent:
t h u s a 3:l m i x t u r e o f e p i m e r s a r e formed,
i s o l a b l e i n 51 % y i e l d ,
t h e major,
&
i n refluxing
w h i c h a r e m o s t s i m p l y i s o l a t e d b y e v a p o r a t i o n o f s o l v e n t and
a l s o undergoes p h o t o b r o m i n a t i o n
The i n t e r m e d i a t e r a d i c a l , t h o u g h ,
with N-chlorosuccinimide f a i l e d
t o s u l f u r y l chloride/azobisisobutyronitrile
m.p.
The v i n y l o g o u s l y p u s h - p u l l a c t i v a t e d p r o a n o m e r i c c e n t r e i n
(m.p.
by p h o t o b r o m i n a t i o n o f
u n d e r a v a r i e t y o f c o n d i t i o n s . However, when e x p o s i n g
2
V e a r e g r a t e f u l to D i p i . I n g .
Hempe f o r e r p e r i m e n t s L e a d i n g to
b'.
r151,
ona t o t h e D e u t s c h e F o r s c h u n g s g e m e i n s c h a f t
-2l0, c h l o r o f o r m ) .
L i 9 a / J J i and t h e Fonds d e r C h e m i s c h e n
(Grant
Industrie f o r financiat
S i n c e h y d r o x y i m i n o f u n c t i o n s a r e o x i d i z e d b y NBS (181 t h e i r
aupport.
u t i l i z a t i o n as t h e c a p t i v e ( " p u l l " ) element o f a c a p t o d a t i v e
system r e q u i r e s p r o t e c t i o n o f t h e oxime h y d r o x y l ,
most suitably effected
by b e n z o y l a t i o n .
Thus,
Experimental
which i s
the easily
3,4,6-Tri-0-benzoyl-a-0-arabino-hexopyrabino-hexopyranos-2-ulosyl
Bromide
~
4
a c c e s s i b l e 1191 p e r a c y l a t e d 1 . 5 - a n h y d r o - D - f r u c t o s e s
and
2
a r e p h o t o b r o m i n a t e d most r e a d i l y t o g i v e t h e o x i m i n o g l y c o s y l
!p
a-bromides
( c f . Experim.)
and
(syrup,
ral;'
= +167',
(z):
3,4,6-Tri-~-benzoyl-1,5-anhydro-D-fructose
(60 m l ) c o n t a i n i n g b r o m i n e (0.96 g o r 0.31 m l .
c h l o r o f o r m ) i n y i e l d s o f 8 7 and 89 I. C l e a r l y , t h e a v a i l -
(1
2 molar
e q u i v . ) and b a r i u m c a r b o n a t e (4.5 g ) b y a 450 H I R h e a t lamp
a b i l i t y o f such o-bromides i n s t a b l e s t o r a b l e f o r m i s c a p a b l e
o r a s t a n d a r d 2 5 0 W t u n g s t e n lamp, p l a c e d a b o u t 10
o f p r o v i d i n g a v e r s a t i l e and e x p e d i e n t e n t r y t o a m i n o s u g a r
f r o m t h e v e s s e l . A f t e r 1 h,,
c o n t a i n i n g o l i g o s a c c h a r i d e s s i m p l y by d i s p l a c e m e n t o f t h e
t i v e l y replaced the s t a r t i n g material,
bromine under Konigs-Knorr t y p e c o n d i t i o n s , subsequent r e -
(chloroform/acetone
d u c t i o n and d e b l o c k i n g .
L e m i e u x ' s n i t r o s o - h a l o g e n i d e p r o c e d u r e 1211, y e t h o l d s t h e
Jl
analogs o f
may e a s i l y b e p r e p a r e d 1161, w h i c h c o n s t i t u t e h i g h l y
v e r s a t i l e b u i l d i n g blocks for the construction o f lactosanine-.
maltosamine-,
and c e l l o b i o s a m i n e - c o n t a i n i n g o l i g o s a c c h a r i d e s .
cm
as e v i d e n c e d b y TLC
E x c e s s i v e b r o m i n e i s removed b y
-
s y r u p which c r y s t a l l i z e s on t r i t u r a t i o n w i t h e t h e r t o a f f o r d
a f t e r r e c r y s t a l l i z a t i o n f r o m t h e same s o l v e n t :
of
z
as f i n e needles,
m . p . 174OC.
[a]:'
=
1.3 g ( 7 8 i)
+185O ( c = 0.5,
chloroform).
(COG1
(1H-dq.
3-H),
5-H),
3
):
6 =
4.56 (1H-dd, A - p o r t i o n o f a n ABX ' s y s t e m
=
(1H-dd,
6.04 ( 1 H - t , 4 - H ) .
7.4 and 8 . 0 ( t w o
10.5, J5,6
NElSlhG
- 15
had q u a n t i t a -
s e q u e n t r e m o v a l o f t h e s o l i d s and t h e s o l v e n t s a f f o r d a
'H-NMR
5
z
b r i e f l y c o n n e c t i n g t h e v e s s e l t o a r o t a t o r y e v a p o r a t o r . Sub-
f o r 6-H2/5-H, 6-H), 4.78
4
t h e more m o b i l e
- 1454
a d d i t i o n a l advantage t h a t d i s a c c h a r i d e - d e r i v e d
and
5:l).
1452 -
T h i s a p p r o a c h has c l o s e a n a l o g i e s t o
[l, 1 2 1 ,
1,4 g. 3 mmole) i s g e n t l y r e f l u x e d i n t e t r a c h l o r o m e t h a n e
m,
B-portion,
6'-H), 4 . 9 0
6.52 (1H-5, 1 - H ) ,
6.54 (1H-d,
9H and 6H, 3 C6H5); J 3 , 4 = J 4 , 5
=
4.5, J5,6, = 2.5, J6,6, = 13 Hz.
185%
p y r a n o s y l Bromide
( l a ) : 3.2
g ( 6 Inmole) o f 3 , 4 , 6 - t r i - C
benzoyl-1,5-anhydro-D-fructose-g-benzoyloxime
10
N-bromosuccinimide
12
11
(2)
1131 and
(1.2 g, 6 . 6 mmole) a r g d i s s o l v e d i n
t e t r a c h l o r o m e t h a n e ( 8 0 m l ) and g e n t l y r e f l u x e d f o r 15 m i n i n
(pNBz = p-nitrobcnzoyl)
b r i g h t l i g h t (250 H t u n g s t e n l a m p p l a c e d n e x t t o t h e r e a c t i o n
vessel).
As with
3
-
5,
t h e 2.6-anhydroheptononitril
p
has a c a p t o -
d a t i v e s u b s t i t u t i o n p a t t e r n a t one o f i t s p r o a n o s e r i c s i t e s ,
and a c c o r d i n g l y ,
y i e l d s the photobromination product
12
(cf.
Experim.) u n c o m p l i c a t e d l y . I t i s t h o u g h t t h a t t h i s approach
when a p p l i e d c o r r e s p o n d i n g l y t o 2 . 6 - a n h y d r o o c t o s o n i c
acid
d e r i v a t i v e s w i l l p r o v i d e a n o v e l and e f f i c i e n t a c c e s s t o
The m i x t u r e i s s u b s e q u e n t l y c o o l e d (OOC),
w i t h s o l i d b a r i u m c a r b o n a t e (15 m i n ) . F i l t r a t i o n and e v a p o r a t i o n t o d r y n e s s l e a v e s a s y r u p u n i f o r m b y TLC ( e t h e r /
p e n t a n e 2 : l ) . w h i c h c r y s t a l l i z e d on t r i t u r a t i o n w l t h e t h e r :
3.5 g ( 8 7 .I)
of
19
a s n e e d l e s , m.p.
78
+261° ( c = 0 . 3 , c h l o r o f o r m ) .
KDO t y p e a n a l o g s .
-
1453 -
the
s u c c i n i m i d e i s f i l t e r e d o f f and t h e f i l t r a t e i s s t i r r e d
- 1455
-
- 79OC. /,XI;'
=
' H - I ~ M R (CDC13):
( b r o a d m,
= 4.7
d
(t,
lH,
J 3 , 4 = J4,5
7.5
a n d 8 . 1 ( t w o m,
3H, 5-H and 6 - H 2 ) .
4-H),
= 10 H z ,
( 1 0 Hz-d,
6.70
6.00
lH,
[7:
3-H).
Viehe,
H.G.
R.
Merenyi,
Stella,
L.
Z.
Janousek, A n g e w .
Chern. 9 1 ( 1 9 7 9 ) 9 8 2 ; Angew. Chem. I n t . E d .
13H a n d 8H, 1 - H a n d 4 C s H 5 ) .
18
Engl.
(1979) 917.
[ 8 j S u p p o r t f o r t h e s e e x p e c t a t i o n s was d e r i v e d f r o m t h e
ready photobromination o f simple captodative analogs
such as methyl methoxyacetate ( 9 1 % [ 7 / ) and methoxya-Bromide o f
__
3,4,5,7-Tetra-~-acetyl-D-gluco-2-heptulo-
(12):
pyranosonic Acid N i t r i l
a c e t o n i t r i l ( 8 7 I [ 7 ] ) and.
A m i x t u r e o f 1 . 7 8 g ( 5 mmol)
of 3 , 4 , 5 , 7 - t e t r a - 0 - a c e t y 1 - 2 , 6 - a n h y d r o - D - g l y c e r o - D - ~ -
(6)
heptonitril
5.6
1 2 3 1 , N - b r o m o s u c c i n i m i d e ( 1 . 0 g.
t h e o-anomer
-
15 m i n w i t h a s t a n d a r d 2 5 0 U t u n g s t e n lamp w h e r e a f t e r
13
[24.,.
(TLC i n c h l o r o f o r m l a c e t o n e 5:1,
C o o l i n g (O'C,
RF
=
0.50
a n d 47 % [ 4 a ] ,
F.W.
0.58
+
p o r a t i o n o f t h e f i l t r a t e i n vacuo l e f t a c r y s t a l l i n e r e s i d u e
t137'
(c
1.1,
=
[.!i2
c o l o r l e s s n e e d l e s ; m . p . 92OC;
r!O]
S i l y l groups a r e removed under p h o t o b r o m i n a t i o n c o n d i t i o n s : H.W.
=
chloroform).
coc13):
1111 J . G e l a s ,
4 O A c ) , 4.17
3H-S,
7'-H),
J3,4
5.25
9.6,
=
6 = 2.02,
(1H-q,
(1H-dd,
7-H),
5-H).
J4,5 = 9.2,
5.32
2.05,
2 . 1 3 a n d 2.19
4.28
(IH-dt,
(1H-d,
3-H),
J6,7
J5,6 = 1 0 . 3 .
5.44
(four
4.39
6-H),
(IH-q,
(1H-t,
a syrup of
4.0,
=
C a r b o h y d r . Chem.
Adv.
Lichtenthaler,
Chem. 4 3 ( 1 9 7 8 )
E.S.H.
39 ( 1 9 8 1 ) 9 5 f f .
Bioekcm.
E l Ashry,
Gockel.
V.H.
21 (1980) 1429.
Tetrahedron L e t t .
4-H);
J6,7,
= 2.0,
L a j i s , J . OFT.
(4).
1131 1 , 2 . 3 - T r i - ~ - b e n z o y l - a - L - ~ - h e x o p y r a n o s - 4 - u l o s e
= -10.4'
l.a]Eo
( c = 1.4,
chloroform),
is
p r e p a r e d f r o m L - r h a m n o s e b y p a r t i a l b e n r o y l a t i o n 1141
= 12.8 Hz.
J7,,,
P i n n i c k , N.H.
371.
1121 F.W.
~ H - N M R ( 3 0 0 MHZ,
P. J a r g l i s , X t h I n t e r n a t i o n a l
on C a r b o h y d r a t e C h e m i s t r y , S i d n e y , A u s t r a l i a ,
J u l y 1 9 8 0 , A b s t r a c t Th 1.
1 h ) , f i l t r a t i o n o f t h e s o l i d s and eva-
11 a s
however, and a p e n t o s e - d e r i v e d
respectively).
Lichtenthaler,
Symposium
w h i c h was c o l l e c t e d a n d r e c r y s t a l l i z e d f r o m e t h e r l p e n t a n e :
1.80 g (83 U ) of
with
I 9 i P o r t i o n s o f t h i s work were communicated p r e v l o u s l y ; see:
t h e educt had been r e p l a c e d q u a n t i t a t i v e l y by t h e f a s t e r
moving
thereof,
of methyl
( 9 0 % !4a,b];
analog t h e y i e l d s were c o n s p i c u o u s l y l o w e r (16 % 14cJ
mmOl)
and b a r i u m c a r b o n a t e ( 0 . 5 g ) i s k e p t u n d e r g e n t l e r e f l u x f o r
10
i n particular,
t e t r a - 0-- a c e t y l - 6 - D - g l u c o p y r a n u r o n a t e
t o 1,2,3-tri-~-benzoyl-n-L-rhamnose
-28'
=
(c
-
200
(m.p.
1.1, c h l o r o f o r m ) ,
=
20loC,
25 % ) a n d o x i d a t i o n
w i t h PCC i n benzene ( 9 4 % ) 1151.
- 1458 -
1456 -
-
;14j
References
[ l j S u g a r E n o l o n e s , P a r t 16.
.z.
. A ; .
-
P a r t 1 5 : P. J a r g l i s ,
140; Angew.
Chem.
2 1 ( 1 9 8 2 ) 141; P n g s w . i k e n . S u p p l .
cngl.
Hempe,
KaJi,
1171 F.W.
Zaikov,
G.E.
b o r d , Pergamon P r e s s ,
[ 3 1 B. H e l f e r i c h ,
, b ~ .
I .
cne,..
i i i s s i r l a t i o i i , Techn.
Hochschule Darmstadt,
to
C h e m i s t r y of t h i , g - G L y c o s i d i e
F.W.
Lichtenthaler,
t o be published.
U. K r a s k a , i a r b o h y i i r .
Lichtenthaler,
h a s . 58 ( 1 9 7 7 )
363.
OxfordINew York 1979.
Bigelow,
N.M.
Hudson,
be s u b m i t t e d .
1161 E .
Bochkov,
C.S.
(1982)
175.
121 A.F.
Fletcher, Jr.,
H.G.
F.W.
[ 1 5 ] W.
C h s m . 94 ( 1 9 8 2 )
I.
Ness,
R.K.
:;o<.. 73 ( 1 9 5 1 ) 2 9 6 .
z. p h y s i o l .
200 ( 1 9 3 1 )
Chem.
( 1 6 1 D.C.
Iffland,
Criner,
G.X.
d.
~ m .: h e " , .
75 ( 1 9 5 3 )
;.,c.
4047.
263;
L.
Zervas,
I . Papadimitrou,
7 3 ( 1 9 4 0 ) 174; J . Lehmann,
be?.
102 ( 1 9 6 9 ) 2 7 4 5 ;
Ber.
Chem. c e s .
Dtsch.
E. P f e i f f e r ,
H. R e i n s h a g e n ,
2
and
J e n k i n s , J.P.H.
I.D.
I191 Educts
4
(m.p.
(m.p.
138
-
89
-
139OC.
90°C,
= -37".
(a1:'
= -70°,
la]:'
chloroform)
c h l o r o f o r m ) were
o b t a i n e d i n y i e l d s o f 9 1 a n d 85 I b y a c y l a t i o n o f t h e
Verheyden, J.G.
Moffat,
J.
Am.
C h e m . S O C . 9 8 ( 1 9 7 6 ) 3346.
respective 1,5-anhydro-D-fructose
141
a ) R.J.
Ferrier,
~ P O - Y SI
( 1 9 7 7 ) 1996; b ) R . J . F e r r i e r ,
Soc.
Chem.
R.H.
Commun.
Furneaux. J .
Chem.
Tyler,
P.C.
Ferrier, ibid.
( 1 9 8 0 ) 1 5 2 3 ; R.J.
chep..
t7.
R. B l a t t n e r ,
Ferrier,
R.H.
A.
Ohno, Y .
Ohnishi.
W.
Timberlake,
M.L.
Tetrahedron L e t t .
Hodges,
ibid.
( 1 9 7 0 ) 4147;
J.
(1973)
Lemieux,
Chrm.
1 2 2 j F.M.
t h e case of glycosides,
i.e.
in
t h e a n o m e r i c C-H b o n d i s
p r e f e r e n t i a l l y homolyzed t o y i e l d lactones:
J . Org. Chem. 4 1 ( 1 9 7 6 ) 2222;
R.J.
R.D.
HcKelvey,
P.C.
T y l e r , J . Chem. S O C . P e r k i n T r a n s I ( 1 9 8 0 ) 2 7 6 2 .
Ferrier,
James,
R.U.
T.L.
Nagabhushan,
48.
Fletcher, Jr.,
Fuchs,
J.
Am.
J . Lehmann,
85
Soc.
Ckem.
chen.
Ber.
108
(1975) 2254.
6
12
and
posure t o i o d i n e vapor,
on TLC b y d r y i n g ( l l O ° C ) .
ex-
s p r a y i n g w i t h 8 0 6 H2S04 and
charring a t llO°C.
Received April 1 5 ,
- 1457 -
Can.
L e m i e u x , K . James, T.L.
C a r b o h y d r . Chem. B i o c h e m . 3 8 ( 1 9 8 1 ) 3 2 3 .
EF:.
1241 V i s u a l i z a t i o n o f
K. Hayday,
I t o , K.
i b i d . 5 1 ( 1 9 7 3 ) 42,
H.G.
( 1 9 6 3 ) 2637;
j61 With an alkoxy f u n c t i o n a t t h e anoneric centre,
Y.
51 (1973) 7 ;
U n g e r , Adu.
(231 8 . Coxon,
309.
resp.
(1980) 1425.
1211 R . U .
Nagabhushan,
( 1 9 6 9 ) 4405;
(201 w i t h
1201 F.W. L i c h t e n t h a l e r , P . J a r g l i s , i e t r n h e d r o n i e i t . 2 1
J.
F u r n e a u x , A u s t . J . C h e m . 33 ( 1 9 8 0 ) 1 0 2 5 .
[S]
oximes
benzoyl c h l o r i d e and p - n i t r o b e n z o y l c h l o r i d e ,
( 1 9 7 8 ) 1 0 1 9 ; C) J . Chem. Sue. P e r k i n
T r a n s I ( 1 9 8 0 ) 1 5 2 8 ; d ) ibid. ( 1 9 8 0 ) 2767;
R.J.
Perkin
:ioc.
- 1459 -
1982
/Z
12 S /
Документ
Категория
Без категории
Просмотров
1
Размер файла
238 Кб
Теги
centred, functionalization, acyloxyimino, glycosyl, novem, oxo, access, bromide, proanomeric, photobromination
1/--страниц
Пожаловаться на содержимое документа