Reaktion #343644

Reaktionsgleichung

HCl

triethylamine

δ-gluconolactone

H-Ile-Phe-OBzl

→

GlcA Ile-Phe-OBzl

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added
2. 2
   workup.STIRRINGthe mixture was stirred for 24 h more
3. 3
   FiltrationThe mixture was then filtered
4. 4
   Sonstigethe filtrate evaporated under reduced pressure
5. 5
   SonstigeThe residue was purified by preparative chromatography on a silica gel column
6. 6
   Wascheneluted with the system chloroform-methanol-water (16:6:1)
7. 7
   Sonstigeyield 1.1 g (58%) after precipitation in ether-petroleum ether (1:1
8. 8
   Sonstige[α]54625 =+1.3° (c=1, DMF)

Vorschrift

To a solution of HCl, H-Ile-Phe-OBzl (1.41 g, 3.5 mmol) in freshly distilled DMF (2 ml) neutralized with triethylamine (0.49 ml, 3.5 mmol), δ-gluconolactone (1.25 g, 7 mmol) and TEA (0.98 ml, 7 mmol) were added. The mixture was stirred at 60° C. for 24 hr. δ-gluconolactane (0.63 g, 3.5 mmol) and TEA (0.43 ml, 3.5 mmol) were then added and the mixture was stirred for 24 h more. The mixture was then filtered and the filtrate evaporated under reduced pressure. The residue was purified by preparative chromatography on a silica gel column eluted with the system chloroform-methanol-water (16:6:1): yield 1.1 g (58%) after precipitation in ether-petroleum ether (1:1, v/v); mp 175°-176° C.; [α]54625 =+1.3° (c=1, DMF); Rf(A) =0.53.

Quelle