New optically pure sugar hydroperoxides. Synhtesis and use for enantioselective oxygen transfer

Tcrmlrcdrm~.

Vol.

53. No. I. pp. 18% 192, 1997

Copyright

0

I!86

Eisevw

Printed in Great Britain.

oo4o-4020/97

PII: SOO40-4020(96)00962-3

Science Ltd

All rights reserved $17.00

+ 000

New Optically Pure Sugar Hydroperoxides. Synthesis and Use For Enantioselective Oxygen Transfer

Hans-Jiirgen Hamann”, Eugen Hefib, Danuta Mostowiczc, Anatoly Mishnevd, Zofia Urbadczyk-Lipkowska’ and Marek Ghmielewski”

’ Instituteof Chemistry, Humboldt University, Berlin, Germany b Institute of Applied Chemistry Berlin-Adlershof,

Berlin, Germany

‘Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland d Latvian Institute of Organic Synthesis, Rga, Latvia

Abstmxt:

2-Deoxy-2-C-methylene methyl glycosides undergo oxidation with hydrogen peroxide in the presence of molybdenum trioxide as catalyst to atford the corresponding anometic hydroperoxides. These- hydroperoxides were used as chiral oxidants of allylic alcohols and prochiralsulfides to offer moderate enantioselectivities which were, however, higher than those reported before for oxidation with optically active peroxyacids. Copyright 0 1996 Elsevier Science Ltd

Enantioselective epoxidation of prochiral allyiic alcohols with optically pure 4,6-di-O-acetyl-2,3-dideoxya-D-threo-hex-2-enopyranosyl

hydroperoxide (1)’ in the presence of Ti(Oi-Pr)r affords chiral epoxy aIcohols.2

The moderate enantiomeric excess observed in these reactions could be ascribed to little differentiation of the neighbourhood of the hydroperoxide group.’ Balasubramanian et a1.3~4 have recently reported on the synthesis of 2-deoxy-2-C-methylene

methyl

glycosides 2 and 3. Oxidation of compounds 2 and 3 with hydrogen peroxide in the presence of molybdenum trioxide as catalyst should provide anomeric hydroperoxide 4 and 5, which are of potential value as chiral oxidants.

185

186

H.-J.HAMANN

elal.

rOBn

TOBfl

rOBn

2:R’=OBn, R*= H

4: R’= OBn, R2 = H

3:R’= H, R2 = OBn

5: R’ = H, R* = OBn

1

6: R’ = OBn, R* =H 7: R’= H, R* = OBn

Results and Discussion Formation of hydroperoxides Anomeric

oxidation

of 2 and 3 was performed

lypophilic character of these compounds, (50-60%).

After chromatographic

respectively.

Hydroperoxides

hydroxymethyl-glycals

as described before for compound

the oxidation required a higher concentration

purification

hydroperoxides

4 and 5 could also be obtained

peroxide

4 and 5 were obtained in 65 and 75% yield, by oxidation

of 4 was proven by x-ray crystallography

produce crystals suitable for diffractometric

under the same conditions

measurements

(cf. Experimental).

and its configuration

of iH NMR and i3C NMR (J cl_& spectral data of both hydroperoxides

of

epoxidation

of olefins by hydroperoxides

Compound

5 did not

was assigned by the similarity

4 and 5.

4 and 5 containing the double bond raises the

question of self-oxidation.

It was of interest to investigate the post-reaction

oxidation

of unsaturated

glycosides,

formation

of hydroperoxides.

hydroperoxides

of hydrogen

6 and 7 v but the yield was lower (30-40%).

The a-configuration

Enantioselective

1, but due to the

mixture obtained after the anomenc

with the aim of finding any side products

that could accompany

It was also of interest to investigate the self-oxidation

the

of the double bond of

4 and 5 in the presence of Ti(O-i-Pr)h. For these studies the glycoside 2 and the hydroperoxide

4 obtained by anomeric oxidation Careful examination

of 2 were selected.

of the post-reaction

mixture obtained after the anomeric oxidation of 2 led to the

isolation of two epoxides 8 (6%) and 9 (2.5%) which accompanied and configuration

the main product 4 (60%). The structure

of 8 and 9 were assigned by ‘H NMR and i3C NMR spectroscopy.

both cases showed spin interaction

NOE experiments

between one of the methylene protons from the epoxide group

anomeric proton. In the case of 8 irradiation

in

and the

of the signal due to H-l (b 4.87) was found to enhance the

intensity of the signal due to one of the methylene protons (b 2.75) by 5%. Conversely, when the corresponding

signal due to the methylene

the signal due to H-l

was enhanced

by 9.6%

corresponding

values found for epoxide 9 amounted to 3% and 10%. In both cases the NOE interactions

between H-3 and epoxide methylene protons were not observed. The NOE-based by x-ray crystallography

of 8 (cf. Experimental).

group was irradiated.

assignments

The

were confirmed

Optically pure sugar hydroperoxides

The 13C spectrum of hydroperoxide in comparison

with hemiacetal

2,3-unsaturated

8 showed ca 10 ppm downfield

9. This observation

hydroperoxides’

187

and their

was in agreement

corresponding

shift of the anomeric carbon atom

with our previous findings noticed for

hemiacetals.’

The

hydroperoxide

enhances the ICi,ui coupling constant in comparison with that found for the hydroxyl counterparts.

group

also

In the case

of 8 it amounts to 178.5 Hz versus 170.6 Hz found for 9. In the presence

of Ti(O-i-Pr)d

hydroperoxide

4 underwent

self-oxidation

to afford epoxide

hemiacetal 10 in a ratio of about 1:2. The hemiacetal 10 exists in CDC4 as a tautomeric anomer lOa, the 1%anomer lob and the open chain hydroxyaldehyde

9 and

mixture of the a-

1Oc as was determined

by ‘H NMR

(cf Experimental). OBn

Bn&H I;Bn!$_

Bnk$

lob

10a Treatment of hydroperoxides

1oc

4 and 5 with acetic anhydride-pyridine

mixture according to the known

procedure ’ afforded unsaturated lactones 11 and 12, respectively. Lactones 11 and 12 have been obtained by an alternative method 6 and have served as acceptors of glycosyl radicals m the synthesis of methylene bridged C-disaccharides’

B”&.

Bntqo

11 Enantioselective

12

oxidation

Ahylic alcohols

13, 14 and 15 were epoxidized

OH

by 4 and 5 in the presence of Ti(O-i-Pr)d in CH$Zlz

HO

Ph-OH

188

H.-J. HAMANN et

After complete conversion

of the hydroperoxide

al.

the enantiomeric excess of the epoxy alcohol formed was

estimated in the reaction mixture by gas chromatography

on cyclodextrin chiral stationary phasesZs The results

obtained for three allylic alcohols 13-15 are summarised in Table 1 Table1 .Enantioselective

Epoxidation

of AhylicAlcohols( 13-15) with Optically Active Hydroperoxides(

4and 5 )

a’Determined by GLC on cyclodextrin phases &s We found lower optical inductions for a-D-arabino-4

than for a-D-lyxo-hydroperoxide

5. In both cases

the best results were obtained with the allylic alcohol 13. The e.e. in the oxidation of 13 with 5 is particularly noteworthy

because it is, so far, the best outcome

obtained when a chiral hydroperoxide

epoxidation

reagent. The values of e.e. obtained by us are higher than those reported

epoxidation

with optically active peroxyacids.

was used as the

before in asymmetric

It is remarkable that it is also possible to epoxidize

alcohol such as 14, because attempts to prepare the corresponding

a tertiary

epoxy alcohol by the Sharpless epoxldation

failed.g Asymmetric corresponding

oxidation

of methylphenyl

sulfide 16 and methylp-tolyl

sulfide 17 by 4 and 5 gave the

sulfoxides with about 25% e.e (Table 2) This value of e.e. is in the range of the best results

obtained

when

hydroperoxides

prochiral

sultides.iO

derived from thiazolidine

derivatives

were examined

Table 2. Asymmetric Oxidation of Prochiral Sulfides with Optically Active Hydroperoxides

Oxidant

Sulfide

T’C

4

16

-20

4

17

5

16

5

17

Sulfoxide e.e. ( % )”

abs.cofign.

25

(-1-W

-20

24

(-MS)

-20

26

(-F(S)

-20

24

(-MS)

“Determined by HPLC on CHRALCEL OD or CHIRALCEL.”

in the oxidation

of

H.-J. HAMANN et ul.

190

70.07, 71.65, 71.75, 73.67, 73.95, 74.90, 78.02, 105.58 (C-l, J ~1.~1178.4 Hz), 115.61, 120.30; MS (LSIMS) m/z: 463 (M+H)‘, 485 (M+Na)‘.

X-Ray stuctural determination

of compounds

5 and 8.

Crystals suitable for x-ray structure determination have been grown from ethyl acetateihexane mixture. Experiment has been performed on the four-circle Enraf-Nonius diffractometer MACH3 using express mode. Unit cell parameters and details of data collection and structure refinement are shown in Table 3. X-ray analysis of the compounds 5 and 8 confirmed the presence of a hydroperoxide unit located in the a-position at the anomeric carbon atom. Both compounds cocrystallize with one molecule of water. As it is shown on Fig.1, the molecule 5 contains one disordered benzyl residue. Further refinement of this group in anisotropic mode showed tendency for further splitting of atomic positions. Due to this not well defined disorder of the benzyl group and probable presence in the crystal of another diffused water molecule, precision of the structure determination is low. Fig. 2 shows three-dimensional structure of the molecule of compound 8. The oxygen atom from epoxy unit belonging to carbon atom C2 is located at a -side of the sugar ring. Table 3. Crystal Data and Structure Refinement for Compounds 5 and 8. Identification code Empirical formula

5 c28 H30 O6 462.5 293(2) 1.54178 orthorhombic P2,2,2,

Formula weight Temperature LK) Wavelength (A) Crystal system Space group Unit cell dimensions (A)

a = 4.7871(s) b = 16.585( 1) c = 36.121(l)

Volume (A3) Z

a = 4.909;1; b = 18.1 H(2) c = 28.224(3) 2510.3(6) 4

1.266

1.104 0.650

1oat; 0.2Xx0.50x0.77

e range for data collection (O) 2.45 to 74.67 Index ranges 0s h $5, -20s k ~0, 05 I 544, Reflections collected 1700 Independent reflections 1700 Refinement method Data/restraints/parameters

C28 H30 07 478.5 293(2) 1S4178 orthorhombic P22 2

2867.8(5) 4

Density (calculated) (Mg/m- 3 ) Absorption coefficient (mm-l) F(000) Crystal size (mm.)

8

0.743 1016 0.11x0.11x0.70 2.90 to 73.85 -6 zzhs 0, 05 k 522, -35
Full-matrix I.s. on F2 1700 IO J 276

1627 I 0 / 330

Goodness-of-tit on F2 Final R indices [L-20(1)]

1.134 Rl=0.1212, wR2=0.3353

1.005 R1=0.0368, wR2=0.0822

R indices (all data)

R1=0.1243, wR2=0.3433

R1=0.0438,

Ap max & min (e Ae3)

0.68 and -0.39

WR2=0.0871

0.11 and -0.12

191

Optically pure sugar hydroperoxides

FILJ1 The arbltrarlly orlented molecule of hydroperoxlde crystalloyraphlc labelhng of atoms

5 with

Fig 3 The arbltrarlly ortented molecule of epoxlde 8 with crystallograptuc labelhng of atoms

H.-J. HAMANN ef al.

192

Transformation of the hydroperoxide 4 in the presence of Ti(O-i-Pr)d Hydroperoxide 4 (0.2 g, 0.4 mmol) in dichloromethane (5mL) was treated with Ti(O-i-Pr)h (O.O12g, 0.04 mmol). After disappearance of the substrate (45 min), the solvent was evaporated and the residue was separated on a silica gel column using hexaniethyl acetate 8:2 v/v as an eluent to afford 10 (0.067 g, 36%) and 9 (0.034 g, 19%) (10): [a]D +5.6 ‘(c 0.8, CH2C12), IR (film): 3404 cm-‘; ‘H NMR (CDC13) selected signals; (lOa) : 5.17 (t,lH, J 1.4, 1.4 Hz, = CHACHB), 5.28 (dd,lH, J 1.3, 2.0 Hz, = CHaCHn), 5.56 (s, lH, H-l); (lob): 5.12 (s, lH, H-l) 5.34 (quintet, lH, J 0.9, 0.9, 18 Hz, = CHACHB), 5.41 (m,lH, J 1.3, 1.3, 1.7 Hz, CHACHB); (10~): 6.16 (s, lH, =CHACHB), 6.61 (t, lH, J 1.1, 1.1 HZ, =CHACHB), 9.48 (s, lH, CHO); MS (LSIMS) m/z 445(M-H)‘, 469 ( M+Na)+ Preparation of lactones. General procedure. 3,4,6-tri-0-benzyl-2-deoxy-2-C-methylene-D-arabino and D-lyxo-hexono-1,Mactone (11) and (12). Hydroperoxide 4 or 5 (0.93 g, 2.0 mmol) was dissolved in dry methylene chloride (20 mL), cooled and treated dropwise with the mixture of acetic anhydride / pyridine 1:2 v/v (1.8 mL) in methylene chloride (10 mL). The mixture was lefl overnight in refrigerator. Subsequently it was poured into ice/ water and extracted with methylene chloride. The extract was washed with water, sodium hydrogen carbonate and brine, dried and evaporated. The residue was purified on a silica gel column by flash chromatography using hexane/ t-butyl methyl ether 6.5:3.5 v/v as eluent to give lactone 11 or 12, respectively, ( 0.72 g, 81% ). Both compounds exhibited the same spectral data as those obtained earlier.6 Enantioselective epoxidation by hydroperoxides 4 and 5. General procedure. All reactions were carried out using hydroperoxide (0.1 mmol), aliylic alcohol (0.1 mmol) and aryl sulfide (0.1 mmol), respectively with 20 mol % Ti(O-i-Pr)4 in the presence of powdered 3A molecular sieves in dichloromethane (3 mL). After complete conversion of the hydroperoxide (detected by TLC) the e.e. of the epoxy alcohol formed was estimated in the resulting reaction mixture by GLC on cyclodextrm stationary phases.2s The enantiomeric excess of the sulfoxide was determined by HPLC on CHIRALCEL OD or CHIRALCEL OB,grespectively. Peak assignment to the R and S configuration of the sulfoxides has been made with authentic sample from FLUKA.

Acknowledgment.Two support.

of us H-J. H.and E. H. wish to thank Deutsche Forschungs-Gemeinschafl

for financial

References

2. 3. 4. 5. 6. 7. 8. 9

10. 11.

Chmielewski, M.; Jurczak, J.; Maciejewski, S. Curb&~& Res., 1987,165, 11 l-l 15. Hamann, H.- J.; Hot?, E.; Chmielewski, M.; Maciejewski, S. Chiralily, 1993, 5, 338-340 Booma, C.; Balasubramanian, K.K. J. Chem. Sot., Chem. Commun., 1993, 1394-1395. Ramesh, N.G.; Balasubramanian, K.K. Tetrahedron, 1995, 51, 255-272 Chmielewski, M. PoZishJ. Chem., 1980, 54, 1913-1921. Kast, J.; Hoch, M.; Schmidt, R.R.; LiebigsAnn. Chem., 1991, 481-485. Giese, B.; Hoch, M.; Lamberth, C.; Schmidt, R.R. Tetrahedron Lett., 1988, 29, 1375-1378. Schurig,V.; Nowotny, H.P., Angew. Chem. 1990, 102, 969-1106; Reiher, T.; Hamann, H.-J., HRC 1992, I5, 346-349. Finn, M.G.; Sharpless, K.B.; in ’ Asymmetric Synthesis ” Ed. Morrison , J.D,: Academic Press, New York, Vol.5, 1985, 247-308 Takata, T.; Ando, W. Bull. Chem. Sot. Jpn. 1986, 59, 1275-1276. Fu, H.; Kondo, H.; Ichikawa, Y.; Lock, G.C.; Wong, C.-H. J.Org.Chem.1992, 57, 7265-7270.

(Received in UK I3 August 1996: revised IO October 1996; accepted 17 Octuber 1996)