References
<A NAME="RG40204ST-1A">1a</A>
Haines AH.
Carbohydr. Res.
2003,
338:
813
<A NAME="RG40204ST-1B">1b</A>
Wang W.
Kong F.
Tetrahedron Lett.
1990,
40:
1361
<A NAME="RG40204ST-1C">1c</A>
Nicolaou KC.
van Delft FL.
Conley SR.
Mitchell JJ.
Jin Z.
Rodríguez RM.
J. Am. Chem. Soc.
1997,
119:
9057
<A NAME="RG40204ST-1D">1d</A>
Hiruma K.
Kajimoto T.
Weitz-Schmidt G.
Ollmann I.
Wong C.-H.
J. Am. Chem. Soc.
1996,
118:
9265
<A NAME="RG40204ST-2A">2a</A>
Dolak LA.
Castle TM.
Laborde AL.
J. Antibiot.
1980,
33:
690
<A NAME="RG40204ST-2B">2b</A>
Naganawa H.
Usui N.
Takita T.
Hamada M.
Maeda K.
Umezawa H.
J. Antibiot.
1974,
27:
145
<A NAME="RG40204ST-2C">2c</A>
Hooper IR.
Aminoglycoside Antibiotics
Springer-Verlag;
New York:
1982.
<A NAME="RG40204ST-2D">2d</A>
Haddad J.
Kotra LP.
Mobashery S. In
Glycochemistry Principles, Synthesis and Applications
Wang PG.
Bertozzi CR.
Marcel Dekker;
New York:
2001.
p.307
<A NAME="RG40204ST-3A">3a</A>
Karpiesiuk W.
Banaszek AJ.
Carbohydr. Chem.
1990,
9:
909
<A NAME="RG40204ST-3B">3b</A>
Paulsen H.
Sumfleth B.
Chem. Ber.
1979,
112:
3203
<A NAME="RG40204ST-3C">3c</A>
Koto S.
Inada S.
Zeu S.
Bull. Chem. Soc. Jpn.
1981,
54:
2728
<A NAME="RG40204ST-3D">3d</A>
Baer HH.
Siemsen L.
Carbohydr. Res.
1986,
146:
63
<A NAME="RG40204ST-3E">3e</A>
Hui Y.
Chang C.-WT.
Org. Lett.
2002,
4:
2245
<A NAME="RG40204ST-3F">3f</A>
Bassily RW.
El-Sokkary RI.
Silwanis BA.
Nematalla AS.
Nahed MA.
Carbohydr. Res.
1993,
239:
197
<A NAME="RG40204ST-3G">3g</A>
Křen V.
Rajnochová E.
Huňková Z.
Dvořáková J.
Sedmera P.
Tetrahedron Lett.
1998,
39:
9777
<A NAME="RG40204ST-4A">4a</A>
Collins PM.
Ferrier FJ.
Monosaccharides, Their Chemistry and Their Roles in Natural Products
John Wiley and Sons;
Chichester:
1995.
p.317
<A NAME="RG40204ST-4B">4b</A>
Lichtenthaler FW. In
Modern Synthetic Methods
Scheffold R.
VCH;
Weinheim:
1992.
p.273
<A NAME="RG40204ST-4C">4c</A>
Bols M.
Carbohydrate Building Blocks
Wiley;
New York:
1996.
p.49
<A NAME="RG40204ST-4D">4d</A>
Danishefsky SJ.
Bilodeau MT.
Angew. Chem., Int. Ed. Engl.
1996,
35:
1380
<A NAME="RG40204ST-4E">4e</A>
Izumi M.
Ichikawa Y.
Tetrahedron Lett.
1998,
39:
2079
<A NAME="RG40204ST-5A">5a</A>
Schmidt RR.
Kinzy W.
Adv. Carbohydr. Chem. Biochem.
1994,
50:
21
<A NAME="RG40204ST-5B">5b</A>
Garg HG.
von dem Bruch K.
Kunz H.
Adv. Carbohydr. Chem. Biochem.
1994,
50:
277
<A NAME="RG40204ST-6A">6a</A>
Schmidt C.
Diploma Thesis
University of Konstanz;
Germany:
1994.
<A NAME="RG40204ST-6B">6b</A>
Buchman DJ.
Dixon DJ.
Hernandez-Juan FA.
Org. Lett.
2004,
6:
1357
<A NAME="RG40204ST-7A">7a</A>
Barroca N.
Schmidt RR.
Org. Lett.
2004,
6:
1551
<A NAME="RG40204ST-7B">7b</A>
Geiger J.
Barroca N.
Schmidt RR.
Synlett
2004,
836
<A NAME="RG40204ST-7C">7c</A>
Khodair AI.
Pachamuthu K.
Schmidt RR.
Synthesis
2004,
53
<A NAME="RG40204ST-7D">7d</A>
Khodair AI.
Winterfeld GA.
Schmidt RR.
Eur. J. Org. Chem.
2003,
1847
<A NAME="RG40204ST-7E">7e</A>
Winterfeld GA.
Schmidt RR.
Angew. Chem. Int. Ed.
2001,
40:
2654 ; Angew. Chem. 2001, 113, 2718
<A NAME="RG40204ST-7F">7f</A>
Das J.
Schmidt RR.
Eur. J. Org. Chem.
1998,
1609 ; and references therein
<A NAME="RG40204ST-8">8</A>
General Procedure for the Michael-Type Addition:
To a solution of anomeric O-unprotected sugar (0.16 mmol) in toluene (1 mL), t-BuOK (0.16 mmol) was added at 0 °C. After 10 min, a solution of 1 (0.19 mmol) in toluene-n-heptane mixture (1:2, 3 mL) was added to it. The reaction mixture was stirred at
the same temperature for the specific period of time given in Table
[1]
. Few drops of HOAc were added to quench the reaction. It was taken in EtOAc, washed
with H2O, and sat. brine, dried over anhyd MgSO4, and concentrated. Purification of the crude residue by chromatography on silica
gel afforded the 1,1-linked oligosaccharide. Selected 1H NMR data (250 MHz, CDCl3): Compound 2a: δ = 5.58 (J
1,2 = 4.3 Hz, 1-Ha), 5.25 (J
1,2 = 3.7 Hz, 1-Hb). Compound 2b: δ = 5.50 (J
1,2 = 4.1 Hz, 1-Ha), 4.56 (J
1,2 = 8.3 Hz, 1-Hb). Compound 3a: δ = 5.56 (J
1,2 = 4.2 Hz, 1-Ha), 5.25 (J
1,2 = 3.9 Hz, 1-Hb). Compound 3b: δ = 5.49 (J
1,2 = 4.2 Hz, 1-Ha), 4.60 (J
1,2 = 8.1 Hz, 1-Hb). Compound 4a: δ = 5.55 (J
1,2 = 4.1 Hz, 1-Ha), 5.16 (J
1,2 = 3.8 Hz, 1-Hb), 5.36 (J
1,2 = 3.3 Hz, 1-Hc). Compound 4b: δ = (J
1,2 = 4.0 Hz, 1-Ha), 4.63 (J
1,2 = 8.1 Hz, 1-Hb), 5.41 (J
1,2 = 3.8 Hz, 1-Hc). Compound 5a: δ = 5.63 (J
1,2 = 4.2 Hz, 1-Ha), 5.11 (J
1,2 = 1.1 Hz, 1-Hb). Compound 6a: δ = 5.60 (J
1,2 = 4.2 Hz, 1-Ha), 5.21 (J
1,2 = 3.9 Hz, 1-Hb). Compound 6b: δ = 5.61 (J
1,2 = 4.1 Hz, 1-Ha), 4.42 (J
1,2 = 8.2 Hz, 1-Hb). Compound 7a: δ = 5.63 (J
1,2 = 4.1 Hz, 1-Ha), 5.41 (J
1,2 = 4.1 Hz, 1-Hb). Compound 7b: δ = 5.34 (J
1,2 = 4.0 Hz, 1-Ha), 5.35 (J
1,2 = 8.7 Hz, 1-Hb). Compound 8a: δ = 5.50 (J
1,2 = 4.1 Hz, 1-Ha), 5.01 (J
1,2 = 3.6 Hz, 1-Hb), 4.36 (J
1,2 = 8.3 Hz, 1-Hc). Compound 8b: δ = 5.29 (J
1,2 = 4.1 Hz, 1-Ha), 5.08 (J
1,2 = 8.2, 1-Hb), 4.51 (J
1,2 = 8.0 Hz, 1-Hc). Compound 9a: δ = 5.23 (J
1,2 = 3.0 Hz, 1-Ha), 5.32 (J
1,2 = 3.5 Hz, 1-Hb).
<A NAME="RG40204ST-9A">9a</A>
Schmidt RR.
Angew. Chem., Int. Ed. Engl.
1986,
25:
212 ; Angew. Chem. 1986, 98, 213
<A NAME="RG40204ST-9B">9b</A>
Schmidt RR.
Klotz W.
Synlett
1991,
168
<A NAME="RG40204ST-9C">9c</A>
Lubineau A.
Escher S.
Alais J.
Bonnaffé D.
Tetrahedron Lett.
1997,
38:
4087