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Synthesis of tetrahydrothiophenes via nucleophilic addition of Harpp's reagent to cyclic carbonates: Application toward the synthesis of breynolide
Tetrahedmn Letters, Vol. 35 No. 36. pp. 6639-6642, 1994 Elsevier ScienceLtd
Printedin Great Britain
oo40-4039/94
57.oo+o.00
0040-4039(94)01437-x
SYNTHESIS OF TETRAHYDROTHIOPHENES VIA NUCLEOPHILIC ADDITION OF HARPP’S REAGENT TO CYCLIC CARBONATES: APPLICATION TOWARD THE SYNTHESIS OF BREYNOLIDE Russell J. Linderman*, Neil S. Cutshall, and Brian T. Becicka Department of Chemistry, North Carolina State University Raleigh, NC 27695 8204
A method for the conversion of a trio1 to a tetrahydrothiophene Abstract: involves ring cleavage of a cyclic carbonate with loss of carbon dioxide.
Breynolide displays
is the aglycon
hypocholesterolemic
breynolide
*b We envisioned
by an application
product
of Breynin
in which the key step
A, a novel sulfur-containing
by Williams
that breynolide
of the electrophilic
and co-workers
*a and of racemic
could be obtained
carbonyl
breynolide
ylide methodology
we have recently developed.
of a method for the construction
the molecule
triol. We now wish to report a novel route for the synthesis
from an unprotected synthesis
Cyclohexane followed followed
trio1 1 was prepared
alternative,
of mesyl chloride
we envisioned
using a cyclic carbonate
ZO&
of the construction
bisimidazole
2
of breynolide
4 did not provide
trio1 5. Reaction
tetrahydrofurau competitive
of THTs and the
of 5 with
(THF) derivative
Subsequent
-Z 3
whereas
the five membered Na2S
the epoxide
surprisingly
carbonyl
4
group for alternate cleanly.
chloride. 5 Mesylation led to good
of the alcohol
4 (30-40%).
As an
group for THT
then provided yields
in the late
of trio1 1 with carbonyl
Improved
the hydroxide
(c408)
strategies
regioselectivity
was
the sulfonate/carbonate
(>70%)
of the cis fused
present in Na2S undergoes
or the primary carbon of the cyclic carbonate
6639
oxide 2 was
ttOQ
could not. Reaction
cyclic carbonate
alcohol
mesylation
(93%)
rather than the THT. Presumably
attack at either the carbonate
to cyclohexene
of the 1,2-diol as the activating
derivative
serve as a protecting
obtained by reaction of the trio1 with trichloroacetyl derived
(THT) portion of
of the epoxy
in low yields of the THT product
(65%)
could also potentially
addition
Formation
+Q
1
formation_ The carbonate
vinyl Grignard
tetraoxide.
and triethylamine.
with Na2.S in DMF *c resulted
IO*
stages
by copper catalyzed
of the vinyl group with osmium
using 1 equivalent
by reaction
of the tetrahydrothiophene
acetal
3 Our synthetic
of the THT portion of bmynolide.
by oxidation
accomplished
that
of (+)-
by Smith and co-
from an acyclic mixed stannyl substituted
strategy required the development asymmetric
glycoside
activity in rats given daily oral doses in the pg/kg range. 1 The synthesis
has been described
workers.
hydrolysis
is described
followed
by
intramolecular process
displacement
of the mesylate
by the primary
alcohol.
All attempts
when Na2S was used as the source of sultirr were unsuccessful.
(BujSn)2S.
as an alternative
6 and CsF did provide formation.
Clearly
source of S 2-. 6 Reaction
the THT 4 in reasonable
the THF by-product
able to turn our attention to the synthesis
yield
without
of the THT portion of breynolide
amide 7 7 followed
of the P-hydroxy
resulted in only a 2-3:l selectivity modification
of each reaction
for the anti-1,3-diol8.
parameter
4
(65%)
(67%)
gave the aldol product
good results in the aldol reaction. then gave the vinyl ketone in very
of Evans and co-workers in stereoselectivi
9 surprisingly
ty. It is interesting
3) McON(II)CH3
_
MegAl @‘C - RT
12ClIO
with
to note
)
(92%)
- OT
-7Ex
6
CM3
THF
We were then
Several trials were carried out for this reduction
without any improvement t):;tE-;E 2) PhCH2OCI
z<
of competitive
of hydroxide.
6 and a-bcnzyloxyacetaldehyde
ketone using the procedure
of IS-crown-
using this protocol.
by addition of vinyhithium
O~J_OTDS pj
amounts
8 The purity of the aldehyde was critical to obtaining
to the Weinreb
good yield. Reduction
detectable
noted above must arise from the presence
aldol reaction 7 of the oxazolidinone
as a single diastereomer. Conversion
this undesired Harpp’s reagent,
of 5 with Harpp’s reagent in the presence
5
Asymmetric
to reduce
We then examined
(82%‘0)
0
OH
011
1) CH$ZI ILi -7V’C
Of1
2) Me&JBH(Ohc)3 HOAC / Tl[F (60%)
that a literature
survey revealed
that the synthesis
of anti- 1.3-diols by the reduction
of aldol products
does not
appear to have been accomplished on unsaturated ketones, nor on systems which boar long aliphatic chains at the r_x-position. These structural features may impair formation of the cyclic transition state thereby leading to reduced stereoselectivity moiety by an alternative addition
for the reduction. approach.
We then sought to improve
Burke and co-workers
of a vinyl group to similar aldehydes
was only accomplished
cuprates derived from a-bromovinyltrimethylsilane. not stereoselective. DIBAL Addition
reduction
Benzylation
investigated
Although
(TMS) substituted
We were gratified
the aldchyde
can be removed
of the addition to observe
phosphine
stabilized
vinyl cuprate was
any detectable
the alcohol 10 in good yield as a single
under a variety reaction
of the desired anti-1,3-diol
by
racemization.
of conditions,
lo we also
of vinyl cuprate as a means to avoid the additional
that the addition
above) then gave the tribenzyllsilyl
9 without
vinyl cuprate provided
the TMS substituent
species also resulted in a single diastereomer (as described
by using tributyl
nucleophilic
of the amide 7 (NaH, BnBr, cat BudNI, OoC - RT in DMF, 98%) followed
the stereoselectivity
TMS removal.
for the anti-13-dial
that stereoselective
The addition reaction of an unsubstituted
(THF, -78 oC, 2 h, 93%) provided
of the trimethylsilyl
diastereomer.
the stereoselection
10 have demonstrated
with the unsubstituted product 11. Benzylation
ether 12. Direct comparison
of the derivatized
steps for
vinyl cuprate of the alcohol vinyl addition
6641
could then be made with the same derivative
product
obtained from lhc reduction
?lI
of the P-hydroxy
OBn
G+-PZrnS
CuI - PBu3 Et20 -7PC
ketone.
11 (75%)
NMR and TLC data clearly revealed
the absence
conversion
provided
to the dimethyl
acetal
acetalization.
Oxidation
of the primary
esterification
with Me1 and potassium
of the syn-1,3-diol hydroxy
alcohol
acctal
isomer.
Ozonolysis
13 by in-situ
to the acid was best carried
carbonate
in acetone.
PDC oxidation
of the vinyl group and
loss of the TBS group
during
out using P102 l1 followed of the acctal intermediate
by
13 gave
t 12
0
0
yields;
ozonolysis
however,
bentyl
ethers.
Pd(OH)2 reaction
ozonolysis
was carried of the benzyl
as the catalyst. mixture.
the carbonate
results
13 The mesylate
of the THT derivative
(0.6 es), In addition
an elimination
Optimal
of the live membered
carbonyl.
product
Repeating
(4.0 eq), 18-Crown-6
18-Crown-6 to recovered identified the reaction
15
(TBAF
accomplished
with PDC
out in the presence
of the TBS group,
(overall
were obtained
convcrtcd
was conlilmcd
starting
in a mixture
of competing
with the same stoichiometry
15 in 71% overall
acetate
material.
19 (24%).
sensitive.
Reaction
at 95oC resulted
of 16 with
in a mixture
of
in only 13% yield along with 30% of formation
of a THF derivative
Only a tract of the alkcnc
was obscrvcd.
up to 85oC for 66 h resulted revealed
was
Using (BqSn)2S
at RT to 750C (50 h) provided
lH and 13C NMR studies
shift for
yield (MsCI, Et3N. THF. -4OoC.
of ethyl acetate and DMF gave better results.
at temperatures
using
to the carbonate
and tcmpcrature
(NMR) as 18. No indication
of the
in ethanol
by the l3C NMR chemical
proved
THT 17 was obtained
oxidation
was added to the
in quantitative
mat&al,
99%) prior to ester, 77%). In
carbonate
16 was then obtained to be solvent
possible
by hydrogenation
if a trace of potassium
but direclly
cyclic carbonate
yield of methyl
of Sudan III to prevent
groups from I4 was then affected
(1.0 eq), and CsF (40 eq) in 5: 1 DMF:EtOAc
(46%) and the unanticipated
removal
(0.2 eq), and CsF (6.0 eq) in acctonitrile
60% yield along with 18% of the starting reaction
WOWz
alcohol
The trio1 was not chromatographed,
1.5 h). Formation (BugSn)2S
observed.
of the primary
12 Removal
yield. The structure
products.
oxidation
of the vinyl group can be readily
either sequence,
0 HZ.
KzC03 @ace) 2) cl3ccocl Et3N. TI 1F -78“C - RT (71%)
14 lower
13
(76%)
THT 17 in
Carrying
in the formation
out the
of the TI-IT
that THT 17 was obtained
as a single isomer. The relative stereochemistry COSY) experiments
verifying
complete
inversion
of the THT C2 substitucnt of stereochemistry
was dctcrmined
by 2D NMR (DEPT,
at Lhe mcsylatc.
16
In summary, cyclic carbonates unanticipated
we have presented
using Harpp’s reagent.
results in the stereoselective
17 in the synthesis
of breynolide
a novel approach In addition, synthesis
will be reported
to the synthesis
the asymmetric of anti-l ,3-diols
synthesis
of THTs by the ring cleavage of THT 17 also revealed
from P-hydroxy
ketones.
of
several
Application
of
in due course.
Acknowledgments Financial support from the National Institutes of Health (GM 47275) is gratefulIy acknowledged. NMR instrumentation at NCSU was made available by grants from the NC Biotechnology Center and the National Science Foundation (CHE-9121380). NSC thanks the Burroughs Wellcome Fund for fellowship support and the NCSW PLU chapter for a travel award. References
and Footnotes
1. Trost, W. IRCS Med. Sot. 1986.14, 905. 2. (a) Williams, D. R.; Jass, P. A.; Tse, H-L. A.; Gaston, R. D. J. Am. Chem. Sot. 1990.1 I2, 45524554. (b) Smith, III, A. B.; Empfield. J. R.; Rivero, R. A.; Vaccaro, H. A.; Duan, J. J. W.; Sulikowski, M. M. J. Am. Chem. Sot. 1992, 114, 9419-9434. See also, (c) Nishiyama, S.; Ikcda, Y.; Yoshida, S. I. Tetrahedron Lett. 1989,30. 105-108. (d) Martin, S. F.; Daniel, D. Tetrahedron Lett. 1993.34, 4281-4284. (e) Smith, III, A. B.; Gallagher, R. T.; Keenan, T. P.; Furst, G. T.; Dormer, P. G. Tetrahedron Letr. 1991, 32, 6847-6850. 3. (a) Linderman, R. J.; Graves, D. M.; Kwochka. W. R.; Ghannam, A. F.; Anklekar. T. V. J. Am. Chem Sot. 1990,112, 7438-7439. (b) Lindcrman, R. J.; Viviani, F. G.; Kwochka, W. R. Tetrahedron Lett. 1992,33, 3571-3574. 4. Kutney, J. P.; Ratcliffe, A. H. Syn. Conzmrtn. 1976, 5, 47-52. 5. Tatsuta. K.; Akimoto, K.; Annaka, M.; Ohno, Y.; Kinoshita, M. Bull. Gem. Sot. Jpn. 1985, 58, 1699- 1706. 6. (a) Harpp, D. N.; Gingras, M. Tetrahedron Left. 1987,28,4373-4376. (b) Gingras, M.; Ghan. T. H.; Harpp. D. N. J. Org. Chem. 1990.55. 2078-2090. (c) Harpp, D. N.; Gingras, M. J. Am. Gem. Sot. 1988,110, 7737-7745. (d) Harpp. D. N.; Gingras, M.; Aida, T.; Chan, T. H. Synthesis 1987. 1122-1124. 7. See. Evans, D. A.; Kaldor, S. W.; Jones, T. K.; Clardy, J.; Stout, T. J. J. Am. Gem. Sot. 1990, ~12,7001-7031, for experimental procedures used for the aldol reaction with this aldehydc. All new compounds were fully charactcnzed by spectral data and MS or combustion analysis. Evans, D. A.; Chapman, K. T.; Carreira, E. M. J. Am. Chrm. Sot. 1988,IIO. 3560-3578. 9: Burke, S. D.; Piscopio, A. D.; Marron, B. E.; Matulcnko, M. A.; Pan, G. Tetrahedron Lett. 1991.32. k-858. 11. Fried, J.; Sih, J. C. Tetrahedron Letr. 1973, 3899-3902. Ultrasound (ultrasonic cleaner bath) was used to promote the oxidation, see: Majetich, G.; Song, J. S.; Leigh, A. J.; Condon, S. M. J. Org. Chern. 1993.58, 1030-1037. 12. Veysoglu, T.; Mitschler, L. A.; Swayze, J. K. Synthesis 1980, 807-810. 13. l3C NMR of the cyclic carbonate CO was observed at 154.9 ppm; IR 1780 cm-l.
(Received in USA 17 June 1994; accepted 22 JuJy 1994)
Printedin Great Britain
oo40-4039/94
57.oo+o.00
0040-4039(94)01437-x
SYNTHESIS OF TETRAHYDROTHIOPHENES VIA NUCLEOPHILIC ADDITION OF HARPP’S REAGENT TO CYCLIC CARBONATES: APPLICATION TOWARD THE SYNTHESIS OF BREYNOLIDE Russell J. Linderman*, Neil S. Cutshall, and Brian T. Becicka Department of Chemistry, North Carolina State University Raleigh, NC 27695 8204
A method for the conversion of a trio1 to a tetrahydrothiophene Abstract: involves ring cleavage of a cyclic carbonate with loss of carbon dioxide.
Breynolide displays
is the aglycon
hypocholesterolemic
breynolide
*b We envisioned
by an application
product
of Breynin
in which the key step
A, a novel sulfur-containing
by Williams
that breynolide
of the electrophilic
and co-workers
*a and of racemic
could be obtained
carbonyl
breynolide
ylide methodology
we have recently developed.
of a method for the construction
the molecule
triol. We now wish to report a novel route for the synthesis
from an unprotected synthesis
Cyclohexane followed followed
trio1 1 was prepared
alternative,
of mesyl chloride
we envisioned
using a cyclic carbonate
ZO&
of the construction
bisimidazole
2
of breynolide
4 did not provide
trio1 5. Reaction
tetrahydrofurau competitive
of THTs and the
of 5 with
(THF) derivative
Subsequent
-Z 3
whereas
the five membered Na2S
the epoxide
surprisingly
carbonyl
4
group for alternate cleanly.
chloride. 5 Mesylation led to good
of the alcohol
4 (30-40%).
As an
group for THT
then provided yields
in the late
of trio1 1 with carbonyl
Improved
the hydroxide
(c408)
strategies
regioselectivity
was
the sulfonate/carbonate
(>70%)
of the cis fused
present in Na2S undergoes
or the primary carbon of the cyclic carbonate
6639
oxide 2 was
ttOQ
could not. Reaction
cyclic carbonate
alcohol
mesylation
(93%)
rather than the THT. Presumably
attack at either the carbonate
to cyclohexene
of the 1,2-diol as the activating
derivative
serve as a protecting
obtained by reaction of the trio1 with trichloroacetyl derived
(THT) portion of
of the epoxy
in low yields of the THT product
(65%)
could also potentially
addition
Formation
+Q
1
formation_ The carbonate
vinyl Grignard
tetraoxide.
and triethylamine.
with Na2.S in DMF *c resulted
IO*
stages
by copper catalyzed
of the vinyl group with osmium
using 1 equivalent
by reaction
of the tetrahydrothiophene
acetal
3 Our synthetic
of the THT portion of bmynolide.
by oxidation
accomplished
that
of (+)-
by Smith and co-
from an acyclic mixed stannyl substituted
strategy required the development asymmetric
glycoside
activity in rats given daily oral doses in the pg/kg range. 1 The synthesis
has been described
workers.
hydrolysis
is described
followed
by
intramolecular process
displacement
of the mesylate
by the primary
alcohol.
All attempts
when Na2S was used as the source of sultirr were unsuccessful.
(BujSn)2S.
as an alternative
6 and CsF did provide formation.
Clearly
source of S 2-. 6 Reaction
the THT 4 in reasonable
the THF by-product
able to turn our attention to the synthesis
yield
without
of the THT portion of breynolide
amide 7 7 followed
of the P-hydroxy
resulted in only a 2-3:l selectivity modification
of each reaction
for the anti-1,3-diol8.
parameter
4
(65%)
(67%)
gave the aldol product
good results in the aldol reaction. then gave the vinyl ketone in very
of Evans and co-workers in stereoselectivi
9 surprisingly
ty. It is interesting
3) McON(II)CH3
_
MegAl @‘C - RT
12ClIO
with
to note
)
(92%)
- OT
-7Ex
6
CM3
THF
We were then
Several trials were carried out for this reduction
without any improvement t):;tE-;E 2) PhCH2OCI
z<
of competitive
of hydroxide.
6 and a-bcnzyloxyacetaldehyde
ketone using the procedure
of IS-crown-
using this protocol.
by addition of vinyhithium
O~J_OTDS pj
amounts
8 The purity of the aldehyde was critical to obtaining
to the Weinreb
good yield. Reduction
detectable
noted above must arise from the presence
aldol reaction 7 of the oxazolidinone
as a single diastereomer. Conversion
this undesired Harpp’s reagent,
of 5 with Harpp’s reagent in the presence
5
Asymmetric
to reduce
We then examined
(82%‘0)
0
OH
011
1) CH$ZI ILi -7V’C
Of1
2) Me&JBH(Ohc)3 HOAC / Tl[F (60%)
that a literature
survey revealed
that the synthesis
of anti- 1.3-diols by the reduction
of aldol products
does not
appear to have been accomplished on unsaturated ketones, nor on systems which boar long aliphatic chains at the r_x-position. These structural features may impair formation of the cyclic transition state thereby leading to reduced stereoselectivity moiety by an alternative addition
for the reduction. approach.
We then sought to improve
Burke and co-workers
of a vinyl group to similar aldehydes
was only accomplished
cuprates derived from a-bromovinyltrimethylsilane. not stereoselective. DIBAL Addition
reduction
Benzylation
investigated
Although
(TMS) substituted
We were gratified
the aldchyde
can be removed
of the addition to observe
phosphine
stabilized
vinyl cuprate was
any detectable
the alcohol 10 in good yield as a single
under a variety reaction
of the desired anti-1,3-diol
by
racemization.
of conditions,
lo we also
of vinyl cuprate as a means to avoid the additional
that the addition
above) then gave the tribenzyllsilyl
9 without
vinyl cuprate provided
the TMS substituent
species also resulted in a single diastereomer (as described
by using tributyl
nucleophilic
of the amide 7 (NaH, BnBr, cat BudNI, OoC - RT in DMF, 98%) followed
the stereoselectivity
TMS removal.
for the anti-13-dial
that stereoselective
The addition reaction of an unsubstituted
(THF, -78 oC, 2 h, 93%) provided
of the trimethylsilyl
diastereomer.
the stereoselection
10 have demonstrated
with the unsubstituted product 11. Benzylation
ether 12. Direct comparison
of the derivatized
steps for
vinyl cuprate of the alcohol vinyl addition
6641
could then be made with the same derivative
product
obtained from lhc reduction
?lI
of the P-hydroxy
OBn
G+-PZrnS
CuI - PBu3 Et20 -7PC
ketone.
11 (75%)
NMR and TLC data clearly revealed
the absence
conversion
provided
to the dimethyl
acetal
acetalization.
Oxidation
of the primary
esterification
with Me1 and potassium
of the syn-1,3-diol hydroxy
alcohol
acctal
isomer.
Ozonolysis
13 by in-situ
to the acid was best carried
carbonate
in acetone.
PDC oxidation
of the vinyl group and
loss of the TBS group
during
out using P102 l1 followed of the acctal intermediate
by
13 gave
t 12
0
0
yields;
ozonolysis
however,
bentyl
ethers.
Pd(OH)2 reaction
ozonolysis
was carried of the benzyl
as the catalyst. mixture.
the carbonate
results
13 The mesylate
of the THT derivative
(0.6 es), In addition
an elimination
Optimal
of the live membered
carbonyl.
product
Repeating
(4.0 eq), 18-Crown-6
18-Crown-6 to recovered identified the reaction
15
(TBAF
accomplished
with PDC
out in the presence
of the TBS group,
(overall
were obtained
convcrtcd
was conlilmcd
starting
in a mixture
of competing
with the same stoichiometry
15 in 71% overall
acetate
material.
19 (24%).
sensitive.
Reaction
at 95oC resulted
of 16 with
in a mixture
of
in only 13% yield along with 30% of formation
of a THF derivative
Only a tract of the alkcnc
was obscrvcd.
up to 85oC for 66 h resulted revealed
was
Using (BqSn)2S
at RT to 750C (50 h) provided
lH and 13C NMR studies
shift for
yield (MsCI, Et3N. THF. -4OoC.
of ethyl acetate and DMF gave better results.
at temperatures
using
to the carbonate
and tcmpcrature
(NMR) as 18. No indication
of the
in ethanol
by the l3C NMR chemical
proved
THT 17 was obtained
oxidation
was added to the
in quantitative
mat&al,
99%) prior to ester, 77%). In
carbonate
16 was then obtained to be solvent
possible
by hydrogenation
if a trace of potassium
but direclly
cyclic carbonate
yield of methyl
of Sudan III to prevent
groups from I4 was then affected
(1.0 eq), and CsF (40 eq) in 5: 1 DMF:EtOAc
(46%) and the unanticipated
removal
(0.2 eq), and CsF (6.0 eq) in acctonitrile
60% yield along with 18% of the starting reaction
WOWz
alcohol
The trio1 was not chromatographed,
1.5 h). Formation (BugSn)2S
observed.
of the primary
12 Removal
yield. The structure
products.
oxidation
of the vinyl group can be readily
either sequence,
0 HZ.
KzC03 @ace) 2) cl3ccocl Et3N. TI 1F -78“C - RT (71%)
14 lower
13
(76%)
THT 17 in
Carrying
in the formation
out the
of the TI-IT
that THT 17 was obtained
as a single isomer. The relative stereochemistry COSY) experiments
verifying
complete
inversion
of the THT C2 substitucnt of stereochemistry
was dctcrmined
by 2D NMR (DEPT,
at Lhe mcsylatc.
16
In summary, cyclic carbonates unanticipated
we have presented
using Harpp’s reagent.
results in the stereoselective
17 in the synthesis
of breynolide
a novel approach In addition, synthesis
will be reported
to the synthesis
the asymmetric of anti-l ,3-diols
synthesis
of THTs by the ring cleavage of THT 17 also revealed
from P-hydroxy
ketones.
of
several
Application
of
in due course.
Acknowledgments Financial support from the National Institutes of Health (GM 47275) is gratefulIy acknowledged. NMR instrumentation at NCSU was made available by grants from the NC Biotechnology Center and the National Science Foundation (CHE-9121380). NSC thanks the Burroughs Wellcome Fund for fellowship support and the NCSW PLU chapter for a travel award. References
and Footnotes
1. Trost, W. IRCS Med. Sot. 1986.14, 905. 2. (a) Williams, D. R.; Jass, P. A.; Tse, H-L. A.; Gaston, R. D. J. Am. Chem. Sot. 1990.1 I2, 45524554. (b) Smith, III, A. B.; Empfield. J. R.; Rivero, R. A.; Vaccaro, H. A.; Duan, J. J. W.; Sulikowski, M. M. J. Am. Chem. Sot. 1992, 114, 9419-9434. See also, (c) Nishiyama, S.; Ikcda, Y.; Yoshida, S. I. Tetrahedron Lett. 1989,30. 105-108. (d) Martin, S. F.; Daniel, D. Tetrahedron Lett. 1993.34, 4281-4284. (e) Smith, III, A. B.; Gallagher, R. T.; Keenan, T. P.; Furst, G. T.; Dormer, P. G. Tetrahedron Letr. 1991, 32, 6847-6850. 3. (a) Linderman, R. J.; Graves, D. M.; Kwochka. W. R.; Ghannam, A. F.; Anklekar. T. V. J. Am. Chem Sot. 1990,112, 7438-7439. (b) Lindcrman, R. J.; Viviani, F. G.; Kwochka, W. R. Tetrahedron Lett. 1992,33, 3571-3574. 4. Kutney, J. P.; Ratcliffe, A. H. Syn. Conzmrtn. 1976, 5, 47-52. 5. Tatsuta. K.; Akimoto, K.; Annaka, M.; Ohno, Y.; Kinoshita, M. Bull. Gem. Sot. Jpn. 1985, 58, 1699- 1706. 6. (a) Harpp, D. N.; Gingras, M. Tetrahedron Left. 1987,28,4373-4376. (b) Gingras, M.; Ghan. T. H.; Harpp. D. N. J. Org. Chem. 1990.55. 2078-2090. (c) Harpp, D. N.; Gingras, M. J. Am. Gem. Sot. 1988,110, 7737-7745. (d) Harpp. D. N.; Gingras, M.; Aida, T.; Chan, T. H. Synthesis 1987. 1122-1124. 7. See. Evans, D. A.; Kaldor, S. W.; Jones, T. K.; Clardy, J.; Stout, T. J. J. Am. Gem. Sot. 1990, ~12,7001-7031, for experimental procedures used for the aldol reaction with this aldehydc. All new compounds were fully charactcnzed by spectral data and MS or combustion analysis. Evans, D. A.; Chapman, K. T.; Carreira, E. M. J. Am. Chrm. Sot. 1988,IIO. 3560-3578. 9: Burke, S. D.; Piscopio, A. D.; Marron, B. E.; Matulcnko, M. A.; Pan, G. Tetrahedron Lett. 1991.32. k-858. 11. Fried, J.; Sih, J. C. Tetrahedron Letr. 1973, 3899-3902. Ultrasound (ultrasonic cleaner bath) was used to promote the oxidation, see: Majetich, G.; Song, J. S.; Leigh, A. J.; Condon, S. M. J. Org. Chern. 1993.58, 1030-1037. 12. Veysoglu, T.; Mitschler, L. A.; Swayze, J. K. Synthesis 1980, 807-810. 13. l3C NMR of the cyclic carbonate CO was observed at 154.9 ppm; IR 1780 cm-l.
(Received in USA 17 June 1994; accepted 22 JuJy 1994)