730
3
Chemical Glycosylation Reactions
⊡ Scheme 59
The discovery (already mentioned) that benzylated or silylated 1-tri-n-butylstannyl derivatives
of glucal undergo palladium-catalyzed cross-couplings with aryl or alkenyl halides [263,264]
facilitated synthesis of naturally occurring C-glycosyl compounds [264]. Interestingly, silylated 1-iodo D-glucal 177, obtained by a two-step procedure consisting of stannylation and tiniodine exchange, can also be coupled with a variety of metalated aromatic derivatives to afford
a high yield of 1-C-arylated compounds 178 ( > Scheme 59) (the best results were obtained
using arylboronic acids and ArZnCl derivatives) [265]. 1-C-arylated compounds, in turn, are
useful precursors of more complex C-glycosyl natural products. In an analogous way, iodoglucal can be obtained in unexpectedly high yield (75%) upon attempted coupling of C-1 stannylated derivative to 3-iodo-2-propyn-1-ol [263].
2-Cyanoglycals [266], which have found application in the synthesis of branched sugars [267],
can be obtained in moderate yields by addition of chlorosulfonyl isocyanate to acylated glycals and treatment of intermediate N-chlorosulfonamides with triethylamine. Potentially useful S-heterocyclic analogs of glycals have been obtained predominantly by adaptation of the
reductive elimination method described in the first part of this chapter [268,269].
References
1. Fischer E, Zach K (1913) Sitzber Kgl Preuss
Akad Wiss 16:311
2. Helferich B (1952) Adv Carbohydr Chem
Biochem 7
3. Nicolau KC, Sorensen EJ (1966) Classics in
Total Synthesis. VCH, Weinheim
4. McNaught AD (1997) Adv Carbohydr Chem
Biochem 52
5. McNaught AD (1997) J Carbohydr Chem
16:1191
6. Blair MG (1954) Adv Carbohydr Chem 9:97
7. Ferrier RJ (1965) Adv Carbohydr Chem
20:67
8. Ferrier RJ (1969) Adv Carbohydr Chem 24:199
9. Ferrier RJ (1967–1999) In: Ferrier RJ (ed)
(1967–1999) A Specialist Periodical Report;
Carbohydr Chem 1–33
10. Danishefsky SJ, Bilodeau MT (1996) Angew
Chem Int Ed Engl 35:1380
11. Seeberger PH, Bilodeau MT, Danishefsky SJ
(1997) Aldrichimica Acta 30:75
12. Di Busolo V, Kim YJ, Gin DY (1998) J Am
Chem Soc 120:13515
13. Thiem J, Karl H, Schwentner J (1978) Synthesis:
696
14. Gervay J, Danishefsky SJ (1991) J Org Chem
56:5448
15. Thiem J, Klaffke W (1990) Top Curr Chem
154:285
16. Grewal G, Kaila N, Franck RW (1992) J Org
Chem 57:2084
17. Seeberger PH, Danishefsky SJ (1998) Acc Chem
Res 31:685
18. Daves JGD (1990) Acc Chem Res 23:201
19. Postema MHD (1995) C-Glycoside Synthesis.
CRC Press, Boca Raton, FL
20. Levy DE, Tang C (1995) The Chemistry of Cglycosides. Pergamon Press, Oxford
3
Chemical Glycosylation Reactions
⊡ Scheme 59
The discovery (already mentioned) that benzylated or silylated 1-tri-n-butylstannyl derivatives
of glucal undergo palladium-catalyzed cross-couplings with aryl or alkenyl halides [263,264]
facilitated synthesis of naturally occurring C-glycosyl compounds [264]. Interestingly, silylated 1-iodo D-glucal 177, obtained by a two-step procedure consisting of stannylation and tiniodine exchange, can also be coupled with a variety of metalated aromatic derivatives to afford
a high yield of 1-C-arylated compounds 178 ( > Scheme 59) (the best results were obtained
using arylboronic acids and ArZnCl derivatives) [265]. 1-C-arylated compounds, in turn, are
useful precursors of more complex C-glycosyl natural products. In an analogous way, iodoglucal can be obtained in unexpectedly high yield (75%) upon attempted coupling of C-1 stannylated derivative to 3-iodo-2-propyn-1-ol [263].
2-Cyanoglycals [266], which have found application in the synthesis of branched sugars [267],
can be obtained in moderate yields by addition of chlorosulfonyl isocyanate to acylated glycals and treatment of intermediate N-chlorosulfonamides with triethylamine. Potentially useful S-heterocyclic analogs of glycals have been obtained predominantly by adaptation of the
reductive elimination method described in the first part of this chapter [268,269].
References
1. Fischer E, Zach K (1913) Sitzber Kgl Preuss
Akad Wiss 16:311
2. Helferich B (1952) Adv Carbohydr Chem
Biochem 7
3. Nicolau KC, Sorensen EJ (1966) Classics in
Total Synthesis. VCH, Weinheim
4. McNaught AD (1997) Adv Carbohydr Chem
Biochem 52
5. McNaught AD (1997) J Carbohydr Chem
16:1191
6. Blair MG (1954) Adv Carbohydr Chem 9:97
7. Ferrier RJ (1965) Adv Carbohydr Chem
20:67
8. Ferrier RJ (1969) Adv Carbohydr Chem 24:199
9. Ferrier RJ (1967–1999) In: Ferrier RJ (ed)
(1967–1999) A Specialist Periodical Report;
Carbohydr Chem 1–33
10. Danishefsky SJ, Bilodeau MT (1996) Angew
Chem Int Ed Engl 35:1380
11. Seeberger PH, Bilodeau MT, Danishefsky SJ
(1997) Aldrichimica Acta 30:75
12. Di Busolo V, Kim YJ, Gin DY (1998) J Am
Chem Soc 120:13515
13. Thiem J, Karl H, Schwentner J (1978) Synthesis:
696
14. Gervay J, Danishefsky SJ (1991) J Org Chem
56:5448
15. Thiem J, Klaffke W (1990) Top Curr Chem
154:285
16. Grewal G, Kaila N, Franck RW (1992) J Org
Chem 57:2084
17. Seeberger PH, Danishefsky SJ (1998) Acc Chem
Res 31:685
18. Daves JGD (1990) Acc Chem Res 23:201
19. Postema MHD (1995) C-Glycoside Synthesis.
CRC Press, Boca Raton, FL
20. Levy DE, Tang C (1995) The Chemistry of Cglycosides. Pergamon Press, Oxford