Perhydropentalenone equivalent from corey's lactone

Perhydropentalenone equivalent from corey's lactone

Tetrahedron Letters,Vo1.24,No.33,pp Printed in Great Britain 3527-3530,1983 0040-4039/83 $3.00 + .OO 01983 Pergamon Press Ltd. PERHYDROPENTALENONEE...

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Tetrahedron Letters,Vo1.24,No.33,pp Printed in Great Britain

3527-3530,1983

0040-4039/83 $3.00 + .OO 01983 Pergamon Press Ltd.

PERHYDROPENTALENONEEQUIVALENT FROM COREY'S LACTONE

N. Mongelli, A. Andreoni, Farmitalia

C. Erba, Via C. Imbonati,

Z-Oxa-bicyclo[3.3.01octane-3,7-diones when submitted

to the Barco procedure

Perhydropentalenone Jones' reagent octane-3-one

derivative

oxidation

yield of the crystalline

reacted

transforms

Vb. Obviously

This chemical

strongly

of 2,5+erhydropentalenedione

an oxa dmethylene

under argon atmosphere by adding H02CCH2C02Et

THF (4 ml) and stirring in dry THF (2.6 x 10 solution potassium

-3

acetate

giving

our working

IVa which, when produces

substrate

(1.3 g) to a suspension dissolution,

in EtOAc-EtOH

w'th the internal

in the synthesis

acid using the Barco procedure

the mixture (90

(7)

Mg ethoxide

is added to a solution

compounds.

is poured

, 2 mol equiv.

(0.57 g) in dry

of the imidazolide

: 10) is warmed in the presence of Michael

product

moie-ty of Vc with imidazole,

Vb

into water and a

addition

of the intermediate

ethyl ester Vc is the major component

addition

3527

(6)

/la:] = -270) 365

ethyl ester complex

of commercial

internal

tion of IVa by CDI.

with

hypothesis.

at r.t., magnesium-monomalonic

precipitate

acetate

in part to Va that reacting

of IVa into Via (oil; [Ci], = -30,

(1.5 g) at 50-70°C to complete

of the cyclopent-2-en-4-one

almost quantitative

change on 2-oxa-bicyclo[3.3.0]octane-3,7-dione

M in 2.6 ml). After 3 hours,

together

crystallizes,

equilibrates

Va. The cyclopenten-4-yl-3-oxo-butanoic

crude precipitate

.

ketone Va (oil; I)L], = +112,

that IVa may be an effective

conversion

until complete

of the collected

B-ketoester

the'latter

(5) givesan

Ta1365 = -365). Alkaline

L21D = -74,

via 6-oxo-R,y-cyclopentenyl-acetic

with an overall yield of 85% confirmed

prepared

of the diol IIIb

IVa into the a,&unsaturated

suggests

The clean and very simple one-pot

Working

tritylation

IVa in THF solution

to completion.

achieving

(1)

of carboprostacyclins

(CDI) in dry THF (1.07 g:O.49 g:2.6 ml/IVa: CDI:THF),

CD1 drives the reaction

thus formally

in the synthesis

(3a,b) , , easily accessible by the nor-bornadiene route

(2)

ketone IVa (m.p. 141-6O;

treatment

behaviour

acid substrates

of perhydropentalenones.

are key intermediates

[ul, =+4.1)

with carbonyldiimidazole

the imidazolide

(Italy)

work as a &oxo-B,y-cyclopentenyl-acetic

+106); when stood at room temperature

=

24 - 20159 Milan0

in the synthesis

as shown in scheme lc4), or by selective

Ihl 365

and C.A. Gandolfi

of ~1S,5R,6S,7R)-7-hydroxy-6-triphenylmethoxymethyl-2-oxabicyclo~3.3.0]

(IIIa, m.p. 106-8O;

(i.e., potassium)

L. Zuliani

(Via) and the adducts

by-product

of the lactone

of the

of the reaction carbonylactiva-

3528

The amounts of the 2'S_ and 2'R-imidazolyl-cyclopentanones, time course of the reaction. very long reaction

Starting

ed by KOAc treatment Since the imidazolide might

explain

Selective,

stereospecific

2,5-diones

is obtained,

and VIIIa NaCl(')

(oil;

mixture;

this adduct

perhydropentalenedione

50% yield after internal Michael

IVb, and after a 1.Cc]D = +67,

is also rapidly convert-

VIb (oil;

].u]D = -72.7).

not described

addition

to the

by Barco et al.,

of the

chromatographed

ethyl ester.

reduction

of the keto group at C-5 of the l-carbethoxy-perhydropentalene-

for example,

by treatment

of Via (1.42 g) with lithium

(1.02 g) in dry THF (15 ml) at 0-5OC for 30 minutes

(aqueous 30% NaH2P04/AcOEt).

related

adduct VIIb (m.p. 94-96O,

adducts are very polar, their formation,

the reported

hydride

the imidazolide

of the reaction

to the corresponding

pure cyclopentenyl-3-oxo-butanoic

aluminum

from the 6-benzyloxymethyl-oxo-lactone,

time (14 h) we obtained

Iu1365 = +448) as a major component

VIIa, b, are closely

In agreement

with Skuballa(8),

followed

the R-ketoester

triterbutoxy by the usual work-up

moiety

is preserved

131 = +81) is submitted to deethoxycarbonylation in DMSO with 365 to give the crystalline tritylketoalcohol, IXa (m.p. 94-96O; I:aJD = +29, [c_x]~~,,, = +63).

Esterification

[CJJ = +40, D

with benzoylchloride

r4365 = -205)

I'UI,= -52,

[a], = -28.9,

in CH2C12-pyridine

whose detritylation

]Q]365 = -183) uncrystallizable

[a:], = -41) and the p-phenylbenzoate, A complicated

mixture

for the internal An alternative

of substances

Michael

addition

route was treatment

was obtained

deethoxycarbonylated

bornadiene

of the Michael

]_a], = -47,

IXd (m.p. 102-3O;

]_C&]365= -277).

alcohol,

reduction

of the isolated

adduct VIb with acetic anhydride

Xa (oil; b],

= -1.7) followed

XI, (oil; ]alD = +53,

as catalyst

keto group. in pyridine

by NaBH4 reduction

+154) [al 365 =

was

IXf, (oil, ]_ti],= +16).

The authors are indebted

to Mr. F. Casabuona

route and to W. Fava and A. Pizzamiglio

They are grateful

IXc, (oil;

to the p-nitrobenzoate

in acidic medium to give the (laR, 4aS, 4S, 5R)-4-benzoyloxymethyl-5-hydroxy-

perhydropentalene-2-one,

Acknowledgements:

IXb, (m.p. 103-5O;

using 1,5-diazabicyclo[4.3.0]non-5-ene

and NaBH4 for selective

the resulting

the benzoate,

gives the 4-hydroxymethyl-bdnzoate in contrast

IXe, (m.p. 79-82";

for 10 hours at r.t. to give the enolacetate in CH Cl - EtOH at -2OOC; 2 2

yields

for synthesis

for the large-scale

to Drs. E. Pella, M. Di Somma and S. De Munari

of IIIa via nor-

development

for analytical

of the method.

determinations.

3529

Scheme

Ia b

1

II

R=H R = -C(C

)

H

6 5 3

a) monoperphthalic

acic

b) ii 0 THF, 2 2'

NaOH

H20,

Scheme

0

0

3

./'

-

QL

,

or

0

IVa

R =

b

R=H

-

,

c

R = CH2-Ph

f

R

1

Eto2C)--fo

,/"

I' ..'

OR

LL 0

R = Tr

trityl

2

.O

IIIa,c

IIIa

lr = trityl

OR

'G Va

Via

R = Tr

R =OH

b

R=Tr

,'=,"I

c

R=lr

R1= CH2C0*Et

b

1 \=N

I

OAc

---

X VIIIa

R = Tr

\

R

VIIa

H

Tr

b

PhCO

Tr

R

1

IX.3 IXh IXC

PhCO

H

IXd

pN02PhC0

H

1X-S

pPh-PhCO

IXF

H

H :H2Ph

R = Tr R = CH2-Ph

c&R

1:l

R = Tr R = CH2-Ph

3530

References

1)

W. Bartmann,

G. Beck, Ang. Chemie.

and footnotes

Int. Edition,

(21),=,

751 (1982) and references

cited therein.

:2)

All the rotatory elemental

powers are measured

analyses

13) a. J.S. Bindra,

of the new compounds

A. Grodski,

J. Chem. Sot., Chem. Commun.,

:4)

C. Erba U.K. Pat. 1.533.207

:51

I. Tgm&k&i,

(6)

(7.3.1979);

L. Gruber, G. Kov&s,

with the calculatedvalue.

151 (1974).

U.K. Pat. 1.533.208

I. Sz6kely

(7.3.1979).

and V. Simonidez,

Tetrahedron

Lett.,

(1976).

A. Bar-co, S. Benetti, 4776

are in good agreement

The

T.K. Schaaf, E.J. Corey, J. Am. Chem. Sot., 95, 7522 (1973);

b. R. Peel, J.K. Sutherland,

4369

in CHCl 3 (1% c). The m.p. are uncorrected.

G.P. Pollini,

P.G. Baraldi

and C.A. Gandolfi,

J. Org. Chem., 4s

(1980).

(7)

D.W. Brooks,

(8)

W. Skuballa

(9)

A.P. Krapcho,

(Received

L.D.L. Lu, S. Masamume,

Angew. Chem. Inst., Ed. Engl., 18, 72 (1979).

and H. Vorbriiggen, Angew. Chem. Int., Ed. Engl., 20, 1046 (1981). Synthesis,

in UK 8 June

82.2 and 893 (1982) and references

1983)

cited therein.