- Email: [email protected]
Stereospecific construction of three contiguous asymmetric centers via cyclic hydroboration
STEREOSPECIFIC CONSTRUCTION OF THREE CONTIGUOUS ASYMMETRIC
CENTERS via CYCLIC HYDRODORATION
Yasushi Yokoyama,’ Hideyuki Kawashima, Masaaki Kohno, Yoshiko Ognwn, md Soil;hi Uchida
Department of Materials Science, Faculty of Engineering, Yokohama Narional University, Tokiwadai, Hodogaya-ku, Yokohama 240. Japan
Abstract:
Diastereospecific
active l&diols, hydroboratinn.
of three contiguous asymmetric centers assembled in optically and S-lactones have been achieved via A(‘-3)-strein controlled cyclic
construction
cyclopentanones,
Kccently we have reported the synthesis of 3,4-unti~4~cyclotrcxyl-3-methylbutane-l,4~diol antilsyn ratio hy a treatment of il~cyclohexylidcne-3 the high diastereoselzctiviry strain”,“
as
merhyl-I-butcne
is that the intermediate
la in 9614
2n wirh rhexylborane.t~* The origin of
A takes the conformation
with the least A(l.3).
depicted in Scheme 1. We here report the application of this strategy to the diastereospecific
construction of three different types of optically active compounds possessing three contiguous asymmetric Ce”tW% Scheme 1
Thex
CH,OBn
c
Me
CH,OBn
the hydrobomcion proceeds in a syn addition manner, control of the geomery
double bond of the 1,Cdiene 2 directly results in the 4,~~onrilyn.selective diol 1. Accordingly,
it was
dials lb and lc, potential
Me
A-major
A-minor As
b
decided to apply this methodology to chiral IA-d&es
synthons
of polypropionsre naturdl prducts,
of the trisnbstituted
preparation of the 3,4-an&1,4~ 2b nnd 2c, from which 1,4-
were expected.
Synthesis
of the diene 2b was started
cleavago
of TUP ether afforded
ao alcohol
double bond of 4b was detcrmincd methylenntion
afforded
followed
by GC analysis
and Homer-Emmons
of 2b described
(R)-3, 5 obtained
alcohol
by Wirtig reaction,
to ix >99/1. Geomettically
reaction.8
2).
Swem
oxidation’8
isomeric
1,4-diene
followed
above in 52% yield in 7 steps (Scheme
from methyl
reduction,
4b in 14% yield for 5 steps (Schenrc
2b in 99% yield in 2 steps.
(S)-3 by Swetn oxidation7b the synthesis
from the knowu
6 Swern oxidation78
hydrony-Z-methylpropcngate.
(S)-3-
benzylntinn,
and
The E/X ratio of the followed
by Wiftig
2c was obtained
by the same reaction
sequencers
from for
3). The Ef,!. ratio of the trisubstituted
double bond of 4c was 2/9X.
Scheme 3. THPO
OH
a, DMSO. (COCl)*, CH2CIp; N NaH, THF (67% in 2 steps). e) pTsOH,
Treatment
methylmorpholine. b) (Me0)*P(O)CH(CH,)C0*Me, c) LiAIH4, THF (84%). d) BnBr. NaH, THF (93%). MeOH (lOO%)~ 1) Ph$=CH2, THF (100% in 2 steps).
of 2h in TIIF (0.1 mol drn~3 concentration)
borane-dimethylsulfide chromatographic
complex
purification,
and 2,3~dimethyl~2~butene
to determine
the optical
reagent
erpcrinrcnt)
definite
C.C. value due to interference
three-step hydroxyl
conversion
or (K)-MTPA depicted
ester
by oxidntinn
The diastereomeric
of Ie described
purity of the monopivalate
4. however,
afforded,
syn-anti
showed
after
iwluted
was
below).
Sb (lanthanide
stereoisomer
a convenient
from
purity (3,4-anti-4.5.
induced
chin.1 shift
failed
to give any
6b (‘II, 13C, 19F NMK, and GC analysis)
hy the inseparable
in Scheme
(1.3 eq, prepared
by ‘H NMR. 9 The other compound
was shown to he N/4
derived from olefinic isomer (i.e., the enantiomer
All attempts
in THF) followed
a mixture of 1,4-diols in 75% yield.
nnri (lb) VI. 3,4~.syn-4,5-anti( n l+diol
at -7X”
derived
from
diffcrcntintion
Id.“’
method
The of rhe
groups.
Similar treatment
of 2c with thexylhorane
95% yield.
The diasterceomneric ruin
only a trxe
amount
ofother
followed
3.4.onri.4.5-syn
diastereoisomers
by chromatogrnphic vs. 3,4-syn-4.5.syn
could be isolated.
purification
Lanthanide-induced
NMR of SC using Eu(Tl’C)~ proved the optical purity of Ic to be 98% e.e.lna
gave 1,4-dial I@ in
was shown
Lo be >98/<2 since
shift experiment
of ‘H
Scheme 4.
5b a)
‘BUCOCI, Pyr
(98%).
Sb
b) PCVC, HP, ACOE,
c) (R)-(+I-MTPA, DCC. DMAP, CH$I~
(89% in z steps).
Scheme 5. OH
OBn
‘BuCOCI.
OH
OBn
sE?oo~ Hoe 1C
The borolanr: R, an uuisolated to give
a cyclopenranone’
(I)~lrcnylborane.
by treatment
I’rrlog~Djerassi
lactonic
of these compounds
of Education,
grearly acknowledged.
in Scheme
followed
After
1, was known
by alkaline reagents
chromatographic
purification,
of 7b with rnCPBA gave 6.lactone
7~9 in 7X% yield, which
was oxidized
hydrogen
in one flask: Sb9 in 71%
to S-lactone
Rc9 by
by Wuts ef nl. and had been converted
to
acid.12
This work was pnnially Ministry
Oxidation
depicted
with the following
of racemic Ilc had been reported
Syntbcsia
a) I~hexBHz.
IJtilirntion
reacted
(4)NaOOH.
in 75% yield.
2c gave a cyclopentanone
mCPBA in 73% yield.
with NaCN and (CF3C0)20
(3)(CF?CO)zO,
7b9 was obtained
Similarly,
of the cyclic hydmhoratinn
2b was successively
(2)NnCN,
cycloPenranone yield.
intermediate
Thus, the l&diene
peroxide.ll
5c
THF; NaCN: &X&O)@;
in natural product synthesis
supportrd
Science,
NaOOH. b) mCPtlA, CHZCIZ,
by a Grant-in-Aid
is now in progress
Cur Scientific
Research
in this laboratory. No. 63740281
and Culture of $npan, and by The Fooundntion “Hattori-Hokokai”.
from the which we
1482
Re~erencrs
and
Notes
I
Y. Yokoyama, H. Kawashima,and H. Masaki, Chem~ LEn, 19X9.4.53.
2
Two other A(1,3)-strain a) D. J. Morgans,
controlled
Jr., Terrultedron
cyclic hydroboration I&f., 1981,22,
processes
have been rcporlcd
on 1.5.dicncs:
3721; b) W. C. Still and K. R. Shaw, ibid., IYXI, 22,
3725. F. Johnson,
Chem. Rev., 1968,68,375.
R. W. Hoffmann,
Chern. Rev., 1989,89,
K. Mo,i nnd S. Sendn, Tcrmhcdron, Hnfh enanfiomers Chemical
of methyl
1841.
1985.4,,54’,.
3-hydroxy-2-methylprpanOateS
were kindly
provided
by Kanegafuchi
Industry Co., which is greatly acknowledged.
a) In order to avoid rxemization was rapidly
removed
Matsumoto,
and (i. Tauchihashi,
h) N-methylmrrrplrolir,~ J. Pacufsky,
of the asymmetric
from the reaction
mixture.
center,
the triethylaminr
See; K. Suzuki,
hydrochloride
K. Tomooka,
formed
E. Katayama,
T.
.1. Am. Chxm~ Sot., 1986, 108, 5221.
was used instead of triedrylamine
for Swern oxidation.
See; S. F. Martin, G.
R. I’. Gist, and W. -C. Lee , J. Am. Chem. Sot., 1989,111,7634.
G. Schmid, T. Fukuyanra, These new compounds
K. Akasaka, and Y. Kishi, .I. Am. Chem. Sac., 1979,101,259. showed
satisfactory
‘H and ‘XC NMR, IR, and high resolution
mass spectral
dam 10
a) In rhe prepnrntinn
nf the dienes 2h and 2~. Swern oxidation
carried out twice.
Extreme
care was taken to avoid racemizalioo
labile intermediate
P,y-unsatmatcd
aldehydt:
which sopposcdly
Wirrig type rencrion combination of the inherenr
was
chiral center on rhe
could bc caused hy the second
Swcrn
oxidation.7 h) All nf the analyses stereoisomer diastcreomeric
showed
the existence
which was believed
to ix derived
dial Id.
We thcrcfbrc
of only
OH
one orher
OBn
from rhe inseparable
assume (bat c.e. of lb is close
HOti ld
I* unity.
11 A. Pelter,K. Smith, M. (1;. Hurchitlgs, and K. Rowe, J. Chem. Sot.. Perkin Tron~. I, 1975, 12Y. 12
I’. G. M. Wurs, M. L. Obrzur, and P. A. Thompson,
(Keceived in Japan 1 December lY!XI)
Tetruhedron
I.efl., 1984,25,
4051.
CENTERS via CYCLIC HYDRODORATION
Yasushi Yokoyama,’ Hideyuki Kawashima, Masaaki Kohno, Yoshiko Ognwn, md Soil;hi Uchida
Department of Materials Science, Faculty of Engineering, Yokohama Narional University, Tokiwadai, Hodogaya-ku, Yokohama 240. Japan
Abstract:
Diastereospecific
active l&diols, hydroboratinn.
of three contiguous asymmetric centers assembled in optically and S-lactones have been achieved via A(‘-3)-strein controlled cyclic
construction
cyclopentanones,
Kccently we have reported the synthesis of 3,4-unti~4~cyclotrcxyl-3-methylbutane-l,4~diol antilsyn ratio hy a treatment of il~cyclohexylidcne-3 the high diastereoselzctiviry strain”,“
as
merhyl-I-butcne
is that the intermediate
la in 9614
2n wirh rhexylborane.t~* The origin of
A takes the conformation
with the least A(l.3).
depicted in Scheme 1. We here report the application of this strategy to the diastereospecific
construction of three different types of optically active compounds possessing three contiguous asymmetric Ce”tW% Scheme 1
Thex
CH,OBn
c
Me
CH,OBn
the hydrobomcion proceeds in a syn addition manner, control of the geomery
double bond of the 1,Cdiene 2 directly results in the 4,~~onrilyn.selective diol 1. Accordingly,
it was
dials lb and lc, potential
Me
A-major
A-minor As
b
decided to apply this methodology to chiral IA-d&es
synthons
of polypropionsre naturdl prducts,
of the trisnbstituted
preparation of the 3,4-an&1,4~ 2b nnd 2c, from which 1,4-
were expected.
Synthesis
of the diene 2b was started
cleavago
of TUP ether afforded
ao alcohol
double bond of 4b was detcrmincd methylenntion
afforded
followed
by GC analysis
and Homer-Emmons
of 2b described
(R)-3, 5 obtained
alcohol
by Wirtig reaction,
to ix >99/1. Geomettically
reaction.8
2).
Swem
oxidation’8
isomeric
1,4-diene
followed
above in 52% yield in 7 steps (Scheme
from methyl
reduction,
4b in 14% yield for 5 steps (Schenrc
2b in 99% yield in 2 steps.
(S)-3 by Swetn oxidation7b the synthesis
from the knowu
6 Swern oxidation78
hydrony-Z-methylpropcngate.
(S)-3-
benzylntinn,
and
The E/X ratio of the followed
by Wiftig
2c was obtained
by the same reaction
sequencers
from for
3). The Ef,!. ratio of the trisubstituted
double bond of 4c was 2/9X.
Scheme 3. THPO
OH
a, DMSO. (COCl)*, CH2CIp; N NaH, THF (67% in 2 steps). e) pTsOH,
Treatment
methylmorpholine. b) (Me0)*P(O)CH(CH,)C0*Me, c) LiAIH4, THF (84%). d) BnBr. NaH, THF (93%). MeOH (lOO%)~ 1) Ph$=CH2, THF (100% in 2 steps).
of 2h in TIIF (0.1 mol drn~3 concentration)
borane-dimethylsulfide chromatographic
complex
purification,
and 2,3~dimethyl~2~butene
to determine
the optical
reagent
erpcrinrcnt)
definite
C.C. value due to interference
three-step hydroxyl
conversion
or (K)-MTPA depicted
ester
by oxidntinn
The diastereomeric
of Ie described
purity of the monopivalate
4. however,
afforded,
syn-anti
showed
after
iwluted
was
below).
Sb (lanthanide
stereoisomer
a convenient
from
purity (3,4-anti-4.5.
induced
chin.1 shift
failed
to give any
6b (‘II, 13C, 19F NMK, and GC analysis)
hy the inseparable
in Scheme
(1.3 eq, prepared
by ‘H NMR. 9 The other compound
was shown to he N/4
derived from olefinic isomer (i.e., the enantiomer
All attempts
in THF) followed
a mixture of 1,4-diols in 75% yield.
nnri (lb) VI. 3,4~.syn-4,5-anti( n l+diol
at -7X”
derived
from
diffcrcntintion
Id.“’
method
The of rhe
groups.
Similar treatment
of 2c with thexylhorane
95% yield.
The diasterceomneric ruin
only a trxe
amount
ofother
followed
3.4.onri.4.5-syn
diastereoisomers
by chromatogrnphic vs. 3,4-syn-4.5.syn
could be isolated.
purification
Lanthanide-induced
NMR of SC using Eu(Tl’C)~ proved the optical purity of Ic to be 98% e.e.lna
gave 1,4-dial I@ in
was shown
Lo be >98/<2 since
shift experiment
of ‘H
Scheme 4.
5b a)
‘BUCOCI, Pyr
(98%).
Sb
b) PCVC, HP, ACOE,
c) (R)-(+I-MTPA, DCC. DMAP, CH$I~
(89% in z steps).
Scheme 5. OH
OBn
‘BuCOCI.
OH
OBn
sE?oo~ Hoe 1C
The borolanr: R, an uuisolated to give
a cyclopenranone’
(I)~lrcnylborane.
by treatment
I’rrlog~Djerassi
lactonic
of these compounds
of Education,
grearly acknowledged.
in Scheme
followed
After
1, was known
by alkaline reagents
chromatographic
purification,
of 7b with rnCPBA gave 6.lactone
7~9 in 7X% yield, which
was oxidized
hydrogen
in one flask: Sb9 in 71%
to S-lactone
Rc9 by
by Wuts ef nl. and had been converted
to
acid.12
This work was pnnially Ministry
Oxidation
depicted
with the following
of racemic Ilc had been reported
Syntbcsia
a) I~hexBHz.
IJtilirntion
reacted
(4)NaOOH.
in 75% yield.
2c gave a cyclopentanone
mCPBA in 73% yield.
with NaCN and (CF3C0)20
(3)(CF?CO)zO,
7b9 was obtained
Similarly,
of the cyclic hydmhoratinn
2b was successively
(2)NnCN,
cycloPenranone yield.
intermediate
Thus, the l&diene
peroxide.ll
5c
THF; NaCN: &X&O)@;
in natural product synthesis
supportrd
Science,
NaOOH. b) mCPtlA, CHZCIZ,
by a Grant-in-Aid
is now in progress
Cur Scientific
Research
in this laboratory. No. 63740281
and Culture of $npan, and by The Fooundntion “Hattori-Hokokai”.
from the which we
1482
Re~erencrs
and
Notes
I
Y. Yokoyama, H. Kawashima,and H. Masaki, Chem~ LEn, 19X9.4.53.
2
Two other A(1,3)-strain a) D. J. Morgans,
controlled
Jr., Terrultedron
cyclic hydroboration I&f., 1981,22,
processes
have been rcporlcd
on 1.5.dicncs:
3721; b) W. C. Still and K. R. Shaw, ibid., IYXI, 22,
3725. F. Johnson,
Chem. Rev., 1968,68,375.
R. W. Hoffmann,
Chern. Rev., 1989,89,
K. Mo,i nnd S. Sendn, Tcrmhcdron, Hnfh enanfiomers Chemical
of methyl
1841.
1985.4,,54’,.
3-hydroxy-2-methylprpanOateS
were kindly
provided
by Kanegafuchi
Industry Co., which is greatly acknowledged.
a) In order to avoid rxemization was rapidly
removed
Matsumoto,
and (i. Tauchihashi,
h) N-methylmrrrplrolir,~ J. Pacufsky,
of the asymmetric
from the reaction
mixture.
center,
the triethylaminr
See; K. Suzuki,
hydrochloride
K. Tomooka,
formed
E. Katayama,
T.
.1. Am. Chxm~ Sot., 1986, 108, 5221.
was used instead of triedrylamine
for Swern oxidation.
See; S. F. Martin, G.
R. I’. Gist, and W. -C. Lee , J. Am. Chem. Sot., 1989,111,7634.
G. Schmid, T. Fukuyanra, These new compounds
K. Akasaka, and Y. Kishi, .I. Am. Chem. Sac., 1979,101,259. showed
satisfactory
‘H and ‘XC NMR, IR, and high resolution
mass spectral
dam 10
a) In rhe prepnrntinn
nf the dienes 2h and 2~. Swern oxidation
carried out twice.
Extreme
care was taken to avoid racemizalioo
labile intermediate
P,y-unsatmatcd
aldehydt:
which sopposcdly
Wirrig type rencrion combination of the inherenr
was
chiral center on rhe
could bc caused hy the second
Swcrn
oxidation.7 h) All nf the analyses stereoisomer diastcreomeric
showed
the existence
which was believed
to ix derived
dial Id.
We thcrcfbrc
of only
OH
one orher
OBn
from rhe inseparable
assume (bat c.e. of lb is close
HOti ld
I* unity.
11 A. Pelter,K. Smith, M. (1;. Hurchitlgs, and K. Rowe, J. Chem. Sot.. Perkin Tron~. I, 1975, 12Y. 12
I’. G. M. Wurs, M. L. Obrzur, and P. A. Thompson,
(Keceived in Japan 1 December lY!XI)
Tetruhedron
I.efl., 1984,25,
4051.