Solid-Phase Synthesis of Carbohydrate Cluster on Tree-Type Linker with Three Types of Orthogonally Cleavable Part

Abstract

We have synthesized octa-, tetra-, and digalactoside based on the three methods of orthogonal cleavage (photo-, base, and acid cleavage) from the solid-supported tree-type linker with three types of orthogonally cleavable parts, simultaneously.

Key words

solid-phase synthesis - orthogonal cleavage - carbo­hydrate cluster - tree-type linker

References

• 1 Amaya T. Tanaka H. Takahashi T. Synlett  2004,  in press 
• 2a Izumi M. Fukase K. Kusumoto S. Synlett  2002,  1409 
• 2b Fürst M. Rück-Braun K. Synlett  2002,  1991 
• 2c Fukase Y. Fukase K. Kusumoto S. Tetrahedron Lett.  1999,  40:  1169 
• 6 Kunz H. Unverzagt C. Angew. Chem., Int. Ed. Engl.  1984,  23:  436 
• 10 Holmes CP. J. Org. Chem.  1997,  62:  2370 

3

Tetra-amine 2 was prepared from the corresponding tetra-azide, which was reported in the preceding paper, see ref. [1]

4

Analytical data for compound 7: ¹H NMR (400 MHz, CDCl₃): δ = 1.18-1.43 (m, 14 H), 1.62 (quintet, 2 H, J = 7.3 Hz), 1.89 (m, 2 H), 2.31 (t, 2 H, J = 7.2 Hz), 2.62 (br s, 8 H), 3.27 (m, 9 H), 3.35 (m, 8 H), 3.64 (m, 4 H), 4.03 (br s, 4 H), 4.22 (br s, 8 H), 4.56 (d, 16 H, J = 5.3 Hz), 5.08 (m, 2 H), 5.21 (br d, 8 H, J = 10.6 Hz), 5.30 (br d, 8 H, J = 17.4 Hz), 5.69 (m, 8 H), 5.91 (ddd, 8 H, J = 5.3, 10.6, 17.4 Hz), 7.64 (m, 2 H). ¹³C NMR (100 MHz, CDCl₃): δ = 23.5, 24.7, 27.2, 28.9, 29.0, 29.1, 33.9, 40.8, 41.3, 54.1, 57.2, 65.7, 70.7, 76.0, 78.8, 81.4, 117.7, 132.8, 156.9, 168.9, 171.4, 177.2. IR(neat): 3334, 2934, 1713, 1532, 1251 cm^-1. MS (ESI-TOF): 1664 [M + H]⁺.

5

Commercially available from Argonaut Technologies, San Carlos, California: http://www.argotech.com.

7

We speculate on the low yield that the acid cleavage proceeded incompletely.

8

Commercially available from Varian, Harbor City, California: http://www.varianinc.com.

9

Analytical data for compound 12: ¹H NMR (400 MHz, D₂O, 30 °C): δ = 1.20-1.43 (m, 14 H), 1.57 (m, 2 H), 1.85 (m, 2 H), 2.24 (t, 2 H, J = 7.7 Hz), 2.71 (brs, 8 H), 2.86 (t, 16 H, J = 6.3 Hz), 3.33-3.47 (m, 33 H), 3.51 (dd, 8 H, J = 7.7, 9.7 Hz), 3.62 (dd, 8 H, J = 3.4, 9.7 Hz), 3.66 (brdd, 8 H, J = 4.3, 7.2 Hz), 3.70-3.79 (m, 16 H), 3.84 (dt, 8 H, J = 5.8, 10.6 Hz), 3.91 (brd, 8 H, J = 2.9 Hz), 4.01-4.13 (m, 12 H), 4.31 (brs, 8 H), 4.40 (d, 8 H, J = 8.2 Hz), 5.12 (quintet, 2 H, J = 5.8 Hz). MS (ESI-TOF): 1638 [M + 2Na]²⁺.

11

¹H NMR spectral data of 14 was identical to that we reported previously, see ref. [1]

12

¹H NMR spectral data of 15 was identical to that we reported previously, see ref. [1]