HYCRON

Allylic hydroxycrotyl-oligoethylene glyco-n-alkanoyl (HYCRON) linker 25 was applied to the synthesis of protected peptides and glycopep-tides [31]. HYCRON is stable to both acidic and basic conditions and is compatible with Boc- and Fmoc-based chemistry. The preparation of this novel linker is only two steps from commercially available materials. H YCRON linker can be cleaved under neutral conditions using Pd catalyst (Scheme 9). 

Seitz O, Kunz H. HYCRON, an allylic anchor for high-efficiency solid phase synthesis of protected peptides and glycopeptides. J Org Chem 1997 62 813-826. 

In the mid to late 1990s, Seitz and Kunzh described a new allylic linker called HYCRON in which a polyether chain is inserted between the allylic group and the carboxy group. The loading on the polymer is best achieved by the preformed handle approach, as outlined in Scheme 4. 

Scheme 4 Synthesis of HYCRON-Anchor Conjugates and Resin Loadingl l...

HYCRON Linker Synthesis of Anchor Conjngates and Resin Loading 0 1... 

Qeavage of Fmoc-Leu-Phe-Ala-OH from Ftaoc-Leu-Phe-Ala-HYCRON-NH-P-Ala-NH-PSty with a Palladium Catalyst and iV-Methylamlme ... 

Liebe and Kunz made further use of the HYCRON linker methodology in the construction of the a2-6 sialyl-TN antigen attached to a portion of the mucin MUCl repeat peptide [104] (O Scheme 20). 

M Gewehr, H Kunz, A Lauterbach, B Loehr, O Seitz. Use of the allylic HYCRON anchor in solid phase peptide synthesis. Proceedings of Innovation and Perspectives in Solid Phase Synthesis. Fourth International Symposium, Edinburgh, 1995, pp 117-120. 

A preformed alanine-HYCRON construct 83 was coupled with the CPG beads using 0-benzotriazol-l-yl-N,N,N, N -tetramethyluronium hexa-fluorophosphate (HBTU) and iV-methylmorpholine (NMM) to give 84. The... 

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