Abstract
The influence of protecting groups on the reactivity of glycosyl acceptors has been
investigated through a series of competitive glycosylation experiments using differently
substituted C2 symmetric d -chiro -inositol derivatives. It has been shown that, for a given glycosyl donor, the protective
group pattern effectively modulates the reactivity of these derivatives in the glycosylation
reaction.
Key words
glycosylation - reactivity - stereoselectivity
References <A NAME="RD06205ST-1">1 </A>
Present address: Departamento de Química Orgánica, Universidad Autónoma de Madrid,
Cantoblanco 28049, Spain; fax +34(91)4973966; email: Belen.cid@uam.es.
2a </A>
Dwek RA.
Chem Rev.
1996,
96:
683
2b </A>
Varki A.
Glycobiology
1993,
3:
97
2c </A>
Carbohydrates in Chemistry and Biology
Vol. 1-4:
Ernst B.
Hart GW.
Sinaӱ P.
Wiley-VCH;
Weinheim:
2000.
3a </A>
Paulsen H.
Angew. Chem., Int. Ed. Engl.
1982,
21:
155
3b </A>
Mootoo DR.
Konradsson P.
Udodong U.
Fraser-Reid B.
J. Am. Chem. Soc.
1988,
110:
5583
4a </A>
Fraser-Reid B.
Wu ZF.
Andrews CW.
Skowronski E.
Bowen JP.
J. Am. Chem. Soc.
1991,
113:
1434
4b </A>
Douglas NL.
Ley SV.
Lücking U.
Warriner SL.
J. Chem. Soc., Perkin Trans. 1
1998,
51
4c </A>
Zhang Z.
Ollman IR.
Ye X.-S.
Wischnat R.
Baasov T.
Wong CH.
J. Am. Chem. Soc.
1999,
121:
734
<A NAME="RD06205ST-5">5 </A> For a review on one-pot glycosylation reactions, see:
Koeller KM.
Wong CH.
Chem. Rev.
2000,
100:
4465
<A NAME="RD06205ST-6">6 </A> See for example:
Ritter TK.
Mong K.-KT.
Liu H.
Nakatani T.
Wong C.-H.
Angew. Chem. Int. Ed.
2003,
42:
5221 ; and references cited therein
7a </A>
Huang X.
Huang L.
Wang H.
Ye XS.
Angew. Chem. Int. Ed.
2004,
43:
5221
7b </A>
Xia J.
Alderfer JL.
Locke RD.
Piskorz CF.
Matta KL.
J. Org. Chem.
2003,
68:
2752
7c </A>
Xue J.
Khaja D.
Locke RD.
Matta KL.
Synlett
2004,
861
<A NAME="RD06205ST-8">8 </A>
Sinaӱ P.
Pure Appl. Chem.
1978,
50:
1437
<A NAME="RD06205ST-9">9 </A>
Boons G.-J.
Zhu T.
Synlett
1997,
809
<A NAME="RD06205ST-10">10 </A>
Crich D.
Dudkin V.
J. Am. Chem. Soc.
2001,
123:
6819
11a </A>
Khiar N.
Martín-Lomas M. In
Carbohydrate Mimics. Concepts and Methods
Chapleur Y.
Wiley-VCH;
Weinheim:
1998.
p.433-462 ; and references therein
11b </A>
Dietrich H.
Espinosa JF.
Chiara JL.
Jiménez-Barbero J.
León Y.
Varela-Nieto I.
Mato JM.
Cano FH.
Foces-Foces C.
Martín-Lomas M.
Chem.-Eur. J.
1999,
5:
320
11c </A>
Martín-Lomas M.
Flores-Mosquera M.
Chiara JL.
Eur. J. Org. Chem.
2000,
1547
11d </A>
Reichardt N.-C.
Martín-Lomas M.
Angew. Chem. Int. Ed.
2003,
40:
4674
12a </A>
Martín-Lomas M.
Flores-Mosquera M.
Khiar N.
Eur. J. Org. Chem.
2000,
1539
12b </A>
Martín-Lomas M.
Khiar N.
Garcia S.
Koessler JL.
Nieto PM.
Rademacher TW.
Chem.-Eur. J.
2000,
6:
3608
12c </A>
Martín-Lomas M.
Nieto PM.
Khiar N.
García S.
Flores-Mosquera M.
Poirot E.
Angulo J.
Muñoz JL.
Tetrahedron: Asymmetry
2000,
11:
37
13a </A>
Cid MB.
Bonilla JB.
Dumarcay S.
Alonso F.
Martín-Lomas M.
Eur. J. Org. Chem.
2002,
881
13b </A>
Bonilla JB.
Muñoz-Ponce JL.
Nieto PM.
Cid MB.
Martín-Lomas M.
Eur. J. Org. Chem.
2002,
889
13c </A>
Cid MB.
Bonilla JB.
Alfonso F.
Martín-Lomas M.
Eur. J. Org. Chem.
2003,
3505
13d </A>
Cid MB.
Alfonso F.
Martín-Lomas M.
Synlett
2003,
1370
13e </A>
Cid MB.
Alfonso F.
Martín-Lomas M.
Carbohydr. Res.
2004,
339:
2303
<A NAME="RD06205ST-14">14 </A>
Cid MB.
Alfonso F.
Martín-Lomas M.
Chem.-Eur. J.
2005,
929
<A NAME="RD06205ST-15">15 </A> Trichloroacetimidates 2 and 10 were prepared as described in:
Kinzi W.
Schmidt RR.
Liebigs Ann. Chem.
1985,
1537
<A NAME="RD06205ST-16">16 </A>
Acceptor 5 was prepared from myo -inositol as reported in ref. 11d.
<A NAME="RD06205ST-17">17 </A>
Cid, M. B.; Alfonso, F.; Martín-Lomas, M. unpublished results .
<A NAME="RD06205ST-18">18 </A>
When d -chiro -inositol was submitted to standard basic benzylation conditions a complex mixture
of products, from which 11 could not been isolated, was obtained. When the tetraol 27 precursor of 9 was treated with BnBr compound 28 , resulting from benzylation of the axially oriented hydroxyl groups, was observed
(Scheme
[3
