Chapter 17
Protecting Groups: Effects on Reactivity, Glycosylation Stereoselectivity, and Coupling Efficiency
Luke G. Green,
Steven V. Ley,
Luke G. Green
Search for more papers by this authorSteven V. Ley
Search for more papers by this authorLuke G. Green,
Steven V. Ley,
Luke G. Green
Search for more papers by this authorSteven V. Ley
Search for more papers by this authorProf. Dr. Beat Ernst,
Prof. Dr. Gerald W. Hart,
Prof. Dr. Pierre Sinaý,
Prof. Dr. Beat Ernst
Institut für Molekulare Pharmazie, Universität Basel, Klingenbergstrasse 50, 4051 Basel, Switzerland
Search for more papers by this authorProf. Dr. Gerald W. Hart
Dept. of Biological Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolf St. Rm., 401 Hunterian Baltimore, MD 21205-2185, USA
Search for more papers by this authorProf. Dr. Pierre Sinaý
Dept. de Chimie, URA 1686, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
Search for more papers by this authorBook Author(s):Prof. Dr. Beat Ernst,
Prof. Dr. Gerald W. Hart,
Prof. Dr. Pierre Sinaý,
Prof. Dr. Beat Ernst
Institut für Molekulare Pharmazie, Universität Basel, Klingenbergstrasse 50, 4051 Basel, Switzerland
Search for more papers by this authorProf. Dr. Gerald W. Hart
Dept. of Biological Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolf St. Rm., 401 Hunterian Baltimore, MD 21205-2185, USA
Search for more papers by this authorProf. Dr. Pierre Sinaý
Dept. de Chimie, URA 1686, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
Search for more papers by this authorSummary
The prelims comprise:
-
Introduction
-
Glycosidic Mechanism
-
Electronic and Torsional Effects
-
Influence of Protecting Group on Donor Reactivity
-
Stereoselectivity
-
influence of the Protecting Group on the Acceptor
-
Steric Effects on Glycosylation
-
Conclusions
References
- P. J. Kocienski, Protecting Groups; Georg Thieme Verlag: Stuttgart: 1994.
- (a)
T. W. Greene,
P. G. M. Wuts,
Protective Groups in Organic Synthesis,
Wiley: New York:
1991
(b)
ref [1]
(c)
M. Bols,
Carbohydrate Building Blocks,
Wiley: New York:
1996
(d)
S. Hanessian,
Preparative Carbohydrate Chemistry,
Marcel-Dekker: New York:
1997
10.1201/9781482273588 Google Scholar(e) G.-J. Boons, Carbohydrate Chemistry, Blackie Academic & Professional: London: 1998.
- B. Capon, Chem. Rev., 1969, 69, 407
- M. L. Sinott, W. P. J. Jencks, J. Am. Chem. Soc. 1980, 102, 2056
- (a) T. L. Amyes, W. P. J. Jencks, J. Am. Chem. Soc. 1989, 111, 7888 (b) M. L. Sinott, Chem. Rev., 1990, 90, 1171
- R. Lemieux, K. B. Hendriks, R. V. Stick, K. James, J. Am. Chem. Soc., 1975, 97, 4056
- A. J. Rhind-Tutt, C. A. Vernon, J. Chem. Soc. 1960, 4637
- T. Ishikawa, H. G. Fletcher, J. Org. Chem., 1969, 34, 563
- R. U. Lemieux, G. Huber, Can. J. Chem., 1955, 33, 128
- (a) P. Delongchamps, C. Moreau, D. Fréchet, P. Atlani, Can. J. Chem. 1972, 50, 3402 (b) P. Deslongchamps, ACS Symposium series: The Anomeric Effect and Associated Stereoelectronic effects; G. R. J. Thatcher Ed.; American Chemical Society: Washington, D. C., 1993; Vol. 549.
- (a) A. J. Ratcliffe, D. R. Mootoo, C. Webster Andrews, B. Fraser-Reid, J. Am. Chem. Soc. 1989, 111, 7661 (b) P. Deslongchamps, P. G. Jones, S. Li, A. J. Kirby, S. Kusela, Y. Ma, J. Chem. Soc., Perkin Trans. 1, 1997, 12, 2621
- D. Y. Curtin, Rec. Chem. Proc, 1954, 15, 111
- There are of course exceptions: (a) where there is no available counter-ion e.g. BF3OEt2 activation of anomeric fluorides and trichloroacetimidates but N.B. the catalyst coordinated ion-pair is also not configurationally stable either. Some silver salts e.g. Ag2CO3, Ag2O, and Ag silicate also operate via a 'push–pull' mechanism—G. Wulff, G. Rohle, U. Schmidt, Chem. Ber. 1972, 105, 111—-however, in this case the initial bromides are not usually configurationally stable. ZnCl2 mediated concerted nucleophilic opening of deactivated glycal epoxides relies on direct attack for selectivity, (b) In cases of solvolysis, as the nucleophile is present in the solvent cage, attack immediately follows activation of the leaving group, leading to product with inversion of the leaving group stereochemistry. A similar special case includes the reaction of trichloroacetimidates with carboxylic acids—R. R. Schmidt, J. Michel Angew. Chem. Int. Ed. Engl. 1980, 19, 731 —-and dibenzyl phosphate— R. R. Schmidt, M. Strumpp, Liebig Ann. Chem. 1984, 680—-where the nucleophile is again present in the solvent cage at the point of activation of the leaving group.
- (a) V. Marousek, T. H. Lucas, P. E. Wheat, C. Schuerch, Carbohydr. Res., 1978, 60, 85 Anomeric perchlorates had been reported previously— K. Igarashi, T. Honma, J. Irisawa, Carbohydr. Res., 1970, 15, 329
- D. Crich, S. X. Sun, Tetrahedron, 1998, 54, 8321
- C. N. Riiber, N. A. Sorensen, Kgl. Norske. Videnskab. Selskabs Skrifter, 1938, 1, 1
- W. G. Overend, C. W. Rees, J. S. Sequeria, J. Chem. Soc. 1962, 3429
- G. N. Richards, Chem. Ind. 1955, 228
- M. S. Feather, J. F. Harris, J. Org. Chem., 1965, 30, 153
- E. A. Kabat, H. Baer, A. E. Bezer, V. Knaub, J. Exp. MEd., 1948, 88, 43
- J. T. Edward, Chem. Ind. 1955, 1102
- B. Fraser-Reid, A. Wu, C. Webster Andrew, E. Skowronski, J. Am. Chem. Soc., 1991, 113, 1434
- C. P. J. Glaudemans, H. G. Fletcher, J. Am. Chem. Soc., 1965, 87, 4636
- N. L. Douglas, S. V. Ley, U. Lücking, S. L. Warriner, J. Chem. Soc., Perkin Trans. 1, 1998, 51
- L. R. Schroeder, J. W. Green, D. C. Johnson, J. Chem. Soc. B, 1966, 447
- (a) S. V. Ley, H. W. M. Priepke, S. L. Warriner, Angew. Chem. Int. Ed. Engl. 1994, 33, 2290 (b) P. Grice, S. V. Ley, J. Pietruszka, H. W. M. Priepke, S. L. Warriner, J. Chem. Soc. Perkin Trans. 1, 1997, 351
- A plausible explanation for the increased importance of the C4 relative to the C3 based upon hyperconjugation with the endocyclic oxygen lone-pairs has been put forward— C. A. A. van Boeckel, T. Beeta, S. F. van Aelst, Tetrahedron, 1984, 40, 4097
- Z. Zhang, I. R. Ollmann, X.-S. Ye, R. Wischnat, T. Baasov, C.-H. Wong, J. Am. Chem. Soc., 1999, 121, 734
- (a) N. L. Douglas, S. V. Ley, H. M. I. Osborn, D. R. Owen, H. W. M. Priepke, S. L. Warriner, Synlett, 1996, 793 (b) U. Berens, D. Leckel, S. C. Oepen, J. Org. Chem. 1995, 60, 8204 (c) J.-L. Montchamp, F. Tian, M. E. Hart, J. W. Frost, J. Org. Chem., 1996, 61, 3897
- That the C4 of galactose has a particular bearing has been noted by others (a) M. Miljkovic, D. Yeagley, P. Deslongchamps, Y. L. Dory, J. Org. Chem. 1997, 62, 7597 (b) O. Kwon, S. J. Danishefsky, J. Am. Chem. Soc., 1998, 120, 1588
- R. U. Lemieux, Adv. Carbohydr. Chem., 1954, 9, 1
- Although participation from other positions has been postulated by many early investigators, there is little evidence to substantiate that this is possible.
- R. U. Lemieux, C. Brice, G. Huber, Can. J. Chem., 1955, 33, 134
- In truth this is a simplification; although attack at CI of 6 leads to the thermodynamic product, kinetic attack occurs first at the carbonyl carbon leading to an orthoester product. If the reaction is performed under acidic conditions, the acid sensitive orthoester rearranges to form the trans glycoside. However if the donor is very deactivated the orthoester may require a higher acid concentration to induce rearrangement which can result in transesterification (to the acceptor alcohol) predominating, especially if an acetate is used. Destabilizing the orthoester by activating the donor or using benzoyl or pivaloyl protecting groups can resolve this problem.
-
This problem has been reported by many other authors (a)
S. Oscarsson,
Topics in Current Chemistry: Glycoscience;
H. Driguuez,
J. Thiem Ed.;
Springer: Berlin Heidelberg,
1997
Vol. 186.
(b)
A. V. Nikolaev,
T. J. Rutherford,
M. A. Ferguson,
J. S. Brimacombe,
Bioorg. Med. Chem. Lett.,
1994,
4,
785
(c)
T. Ziegler,
B. Adams,
P. Kovác,
C. P. J. Glaudemans,
Carbohydr. Chem.,
1990,
9,
135
(d)
H. Jiao,
O. Hindsgaul,
Angew. Chem. Int. Ed. Engl.,
1999,
38,
346
10.1002/(SICI)1521-3773(19990201)38:3<346::AID-ANIE346>3.0.CO;2-L CAS Web of Science® Google Scholar(e) N. Kochetkov, The Synthesis of Polysaccharides in The Total Synthesis of Natural Products; J. ApSimon Ed.; Wiley-Interscience: New York, 1992; Vol. 8, p 245.
-
D. Depré,
A. Düffels,
L. G. Green,
R. Lenz,
S. V. Ley,
C.-H. Wong,
Chem. Eur. J.,
1999,
5,
3326
10.1002/(SICI)1521-3765(19991105)5:11<3326::AID-CHEM3326>3.0.CO;2-Q CAS Web of Science® Google Scholar
- J. Arnop, M. Haraldsson, J. Lönngren, J. Chem. Soc., Perkin Trans. 1 1982, 1841
- J. M. Frechét, C. Schuerch, J. Am. Chem. Soc., 1972, 94, 604
- J. M. Frechét, C. Schuerch, Polymer Supported Reactions in Organic Synthesis; P. Hodge Ed.; Wiley: Chichester, 1980.
- Schroeder et al, demonstrated that α-selectivity increased with increasing size of the alcohol— L. R. Schroeder, J. W. Green, D. C. Johnson, J. Chem. Soc. B 1966, 447
- J. E. Wallace, L. R. Schroeder, J. Chem. Soc., Perkin Trans. 1 1976, 1938
- (a)
D. K. Baeschlin,
A. R. Chaperon,
V. Charbonneau,
L. G. Green,
S. V. Ley,
U. Lücking,
E. Walter,
Angew. Chem. Int. Ed. Engl.
1998,
37,
3423
10.1002/(SICI)1521-3773(19981231)37:24<3423::AID-ANIE3423>3.0.CO;2-I CAS PubMed Web of Science® Google Scholar(b) A. S. Campbell, B. Fraser-Reid, J. Am. Chem. Soc. 1995, 117, 10387 (c) T. G. Mayer, B. Krazer, R. R. Schmidt, Angew. Chem. Int. Ed. Engl. 1994, 33, 2177 (d) C. Murakata, T. Ogawa, Carbohydr. Res., 1992, 235, 95
- The Δ2 effect— R. E. Reeves, Adv. Carbohydr. Chem. 1960, 15, 11—-the axial oxygen at C2 serves to both to reinforce the anomeric effect, further lowering the ground state energy of the α-leaving group relative to the β-leaving group and sterically shields the β-face thus promoting α-glycosidation.
- W. S. Kim, S. Hosono, H. Sasai, M. Shibisaki, Heterocycles 1996, 42, 795 —-perchlorate counter-ions have been proposed to provide higher α-selectivities than triflates owing to their slightly reduced fugacity and ether type solvents at room temperature also serve to promote α-selectivity (see chapter on solvent effects).
-
Others have used deactivated fucosyl donors—(a)
M. Djeter,
H. M. Flowers,
Carbohydr. Res.
1972,
23,
41
10.1016/S0008-6215(00)81575-X Google Scholar(b) V. Behar, S. J. Danishefsky, Angew. Chem. Int. Ed. Engl. 1994, 33, 1468 (c) R. Windmüller, R. R. Schmidt, Tetrahedron Lett. 1994, 65, 7927 (d) T. Kiyoi, Y. Nakai, H. Kondo, H. Ishida, M. Kiso, A. Hasegawa, Bioorg. Med. Chem., 1996, 4, 1167
- J. E. Wallace, L. R. Schroeder, Chem. Soc., Perkin Trans. I 1976, 1633
- R. Eby, C. Schuerch, Carbohydr. Res., 1974, 34, 79
- P. Sinay, Pure Appl. Chem., 1978, 50, 1437
- Boons and Zhu have exploited this effect for the synthesis of small oligosaccharides— G.-J. Boons, T. Zhu, Synlett 1997, 809
- (a) V. Pozsgay, Carbohydrates: Synthetic Methods and Applications in Medicinal Chemistry: Synthesis of Oligosaccharides Related to Plant, Vertebrate, and Bacterial Cell-wall Glycans: H. Ogura, A. Hasegawa, T. Suami Ed.; Kodansha, VCH: Tokyo, New York, 1992, p 188 (b) H. Paulsen, W. Rauwald, U. Weichert, Liebig. Ann. Chem. 1988, 75 (c) K. Jaarsveld Zegelaar, S. A. W. Smits, G. A. van der Marcel, J. H. van Boom, Bioorg. Med. Chem., 1996, 4, 1819
- e.g. for sulfoxides D. Kahne, S. Raghavan, J. Am. Chem. Soc., 1993, 114, 1580
- For glycosyl bromides under halide catalysis this is the rate determining step [6].
- N. M. Spijker, C. A. Boeckel, Angew. Chem. Int. Ed. Engl., 1991, 30, 180
- D. Crich, S. X. Sun, J. Org. Chem., 1997, 62, 1198
- inter alia (a) M. Wakao, Y. Nakai, K. Fukase, S. Kusumoto, Chem. Lett. 1999, 27 (b) R. Rodebaugh, S. Joshi, B. Fraser-Reid, H. M. Geysen, J. Org. Chem., 1997, 62, 5660
- X.-X. Zhu, M.-S. Cai, R.-L. Zhou, Carbohydr. Res., 1997, 303, 261
- (a) Y.-M. Zhang, A. Brodzky, P. Sinaÿ, G. Saint-Marcroux, B. Perly, Tetrahedron: Asymmetry 1995, 6, 1195 (b) V. Pozsgay, E. P. Dubois, L. J. Pannell, J. Org. Chem., 1997, 62, 2832
- K. Toshima, K. Tatsuta, Chem. Rev., 1993, 93, 1503
- These include: (a) direct alkylation of the anomeric position— R. R. Schmidt, Angew. Chem. Int. Ed. Engl., 1986, 25, 212 (b) attempts at SNi based strategies—(i) M. E. Behendt, R. R. Schmidt, Tetrahedron Lett., 1993, 34, 10733 (ii) T. Iimori, T. Shibizaki, S. Ikegami Tetrahedron Lett., 1996, 37, 2267 iii) G. Scheffler, R. R. Schmidt Tetrahedron Lett. 1997, 38, 2943 iv) G. Scheffler, R. R. Schmidt J. Org. Chem., 1999, 64, 1319 (c) tethered strategies (see Chapter 16 (?) on β-mannose). (d) redox glycosylation— A. G. M. Barrett, B. C. B. Bezuidenhoudt, A. F. Gasiecki, A. R. Howell, M. A. Russell, J. Am. Chem. Soc., 1989, 111, 1392 (e) acetal reduction— H. Ohtake, T. Iimori, S. Ikegami Tetrahedron Lett., 1997, 38, 3413
- H. Waldmann, U. Schmid, Chem. Eur. J., 1998, 3, 494
- C. Schuerch, Acc. Chem. Res., 1973, 6, 184
- H. Paulsen, Angew. Chem. Int. Ed. Engl., 1982, 21, 155
- F. Baressi, O. Hindsgaul, Modern Synthetic Methods: Glycosylation Methods in Oligosaccharide Synthesis, B. Ernst, C. Leuman, Ed.; VCH, Basel, 1995.
