Tetrahedron Printed in
Letters,Vol.25,No.3,pp Great Britain
A HIGHLY
REGIO-
OLEFINS
AND
VIA
AN
0040-4039/84 $3.00 + 01984 Percamon Press
313-316,1984
STEREOSELECTIVE
ELIMINATION
OF
SYNTHESIS
OF
.oo Ltd.
INTERNAL
TRIMETHYLSTANNYL
GROUP
* Eigoro
Masahiro
Murayama,
Department
Uematsu,
of Applied
Hiroyuki
Chemistry,
Shinjuku-ku,
Abstract:
Internal
thionium
ion
gave
stereoselectivity trialkylstannyl
Some of
time
of
produce
trans
via
or
Macdonald
ago,
reactions
= 0 or
The
resulting
group
finding
to 2)
while that
-
or
produce
and
the
reaction
in
group
in
the
the
high
of
compounds
yield
and
a hydride
carried
having
regio-
p to
transfer modes
of
olefins.
and
the
are
a
b)
bond
a hydride 1)
We
(path
strictly
,2 3
two
formation
to
p to
path
b
- n=3,
4
from
on
n the
PhSm
= 3 or alkyl
the
1 using
predominated when
dependent
the
investigated
derived a)
reaction
found
then
predominated
b
313
internal and
compounds
cyclization (path
the
carbon-carbon
alkyltin(IV)
that
out
electrophiles,
transfer
terminal of
found
@-hydride
path PhS
Japan
with
carbon-centered
reaction
chloride,
his
either
products
ion-induced
2,
olefins
Sato
3,
Ookubo
alkyltin(IV)
1,6-transfer
and
having
cyclization
titanium(IV)
1,5-
University,
160,
secondary
Tadashi
group.
trialkylstannyl thionium
of
internal
tetraalkylstannanes
modes
n
reaction
Waseda
Tokyo
and
Nishio,
when 4. 3) chain
314
length
prompted
Hb-transfer Actually,
us
or
to
cyclization
a hydride
stereoselectivity synthetic
examine
method
in
transfer was
of
whether the with
observed,
internal
there
exists
a selectivity
secondary
alkyltin(IV)
excellent
regioselectivity
and
the
olefins
reaction
with
trans
compounds
turned
out
well
to be
(Scheme as
a useful
4 R
a
= Me,
n=l
d
R = Me,
n=3
e
R
n=4
b
R
= Me,
n=2
C
R = Et,
n=2 Scheme
I.
as
2
Ha-,
geometry.
f
Table
among
Elimination
of
the
I
Secondary
Temperature OC
Alkyltin(IV)
= Me,
Alkyltin(IV)
Product
a)
Compound.
Yieldb)
trans
cis
(sa)
(%)
(%)
100
0
-100
-78
95
9e
2
0
90
91
9
91
80
20
2a -
rt
I()
i-
-2b
0
2?G!
91
84
16
-2c
0
2JG
85
100
0
4d (= 2) -
93
99
1
4e -
96
90
-2d
-78
-2e
0
a)
Chlorides
b)
Yields
2 were
dichloromethane are
based
treated for
with
1 eq
of
titanium(IV)
chloride
15 min.
upon
the
sulfides
before
the
chlorination.
10
in
I).
315
The
secondary
of
titanium(IV)
chloride,
through
Ha-transfer,
while
through
Hb-transfer.
The
1 eq
structure
was
absorption protons
966 cm
observed
in
GLC.
known
routes,
The
reaction and
2b,&, and
_2e
the
at
the
smoothly
at
-78OC,
temperature,
used
The process
the
lower
the
absence in
the
the
Extremely responsible
the
the
the
could
thermodynamically
stable
migrating The
hydrogen
secondary
alkenes
5 as
1 were
treated
alcohols converted in
THF.4)
6
in to
in
with 49
underwent
UV-Irradiation
of
and
4d The
and
the
strong
two
olefinic on
were
prepared
&
4e -
trans
isolated
The
(3)
lower
IR
a by
the
products
group
center
of
and
1,5-
II.
compounds the
the
2a --
The
Grignard or
tosylates 8 by
crude
- 2e
oil
g
the
vs.
the -2~).
cyclization steric
stannyl
group. might
reaction.
be
The
intermediate
high of
group
and
position. were
prepared
compounds to
2 derived
in
when
trimethylstannyl
epoxides
treatment
trans
(2b -
transfer
a cyclic the
The
bulkier
the
proceeded
improved
that
present
nor
reaction
substantial
to
anti-coplanar
aldehydes The
the
bound
assuming
compounds
yields.
to
in which the
became
1,6-hydride
in
by
was
indicate
due
carbanion
Scheme
higher
quite
was
transfer
(4)
however,
would
unfavorable
occupy
the
was
products
1,5-hydride
the
while
selectivity
stereoselectivity.
stannyl
explained
selectivity
trans
required
Among
transfer,
cyclization
better
transfer,
(1)
follows.
The
of
Although
transfer
as
1,5-hydride
(2)
is
of
only
bond.
appropriate
alkyltin(IV)
are
trace
conformation,
the
- 82%
results
any
of
atom
I.
between
samples
with
respectively,
olefins
Table
Hz
to 2
treatment
2,
in view
the
contain
alkyltin(IV)
shown
the
regioselectivity be
of
transfer.
processes
stereoselectivity
and
the
15.2
1,6-hydride
cyclized
high
of
spectra
1,6-hydride
case
in
products
constant
-2d
the
secondary
facile for
major
1,6-hydride
P-position
of
the
temperature.
present
at
not
with
B,
upon
corresponding
s-arized
of
and
double
the
z,
references.
only did
in
on
interaction
the
-2a
and
2,
corresponding
features
inevitably
group
as
olefins
produced
NMR
isomers
2b,
are
of
400-MHz
and
stereoselectivity
-2e
coupling
cis
of
and
results
The
products
observed
-2d
and
the
&,
produced
all
underwent
isomers
compounds
for
modes,
position
alkyl
-1
characteristic
possible
high
assigned
at
preparative the
alkyltin(IV)
with thiophenol
from
from
give from
w-bromo-l-
the
bromides
secondary 6
(76
- 91%)
were
trimethylstannyllithium gave
sulfides
2,
316
LiSnMe, 4 2)
RCH2CH0
or
“‘To
2
ii
X=H
z
X
Scheme
accompanied to
by
thiophenol
diphenyl by
treating
triphenylphosphine. of
the
The an
2 with
of
mixture
overall
byproduct
with
yields
2
in
lithium
of 2
z were
carbon
yield
removed
aluminum
from
in
quantitative
was
as
48
after
reducing
hydride
or
- 5146.
Treatment
tetrachloride
an
almost
it
gave
pure
oil
after
the
succinimide.
present
internal
The
II
N-chlorosuccinimide
sulfides
filtration
the
The
sulfides
a-chlorinated
disulfide.
= Ts
reaction
trans
offers
double
bond
a valuable
into
an
approach
organic
for
molecule
the
introduction
regio-
and
of
stereo-
selectively.
References 1)
T.
L.
Macdonald
and
S.
Mahalingam,
J.
T.
L.
Macdonald
and
S.
Mahalingam,
Tetrahedron
Macdonald, (1981); 2)
Y.
B.
M.
I.
Peterson
3) E.
Trost
Ohta,
E.
Murayama,
and
I.
Fleming,
M.
J.
S.
Filippo,
E.
C.
Ashby in
M.
and
Chemical
(Received
Mahalingam,
Ueno,
Murayama,
the 4)
S.
Uematsu,
Society
of
Jr.,
and
and
Japan
R.
D.
E.
and
M.
Okawara,
A.
O'Dell,
Amer.
Chem.
Chem.
J.
Silbermann, ibid.,
1983)
J. 104,
22,
Amer.
Chem.
m,
Sato, 1983, Amer.
6144
103,
2113
2077
(1980);
(1981);
Sot.,
6529
T.
April
Lett.,
Sot.,
Nakano, Kyoto,
102,
Lett.,
Lett.,
and
Sot.,
Tetrahedron
Tetrahedron
Japan,
DePriest,
1 October
and
J.
J.
Amer.
3,
T.
L.
log,
6767
2577
(1982).
(1981);
2179. 47th
National
Abstr. Chem.
(1982).
No.
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Meeting
of
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2831
(1982);