Tandem Staudinger–Aza‐Wittig Templated Reaction: De Novo Synthesis of Sugar–Ureido Cryptands

Abstract

A templated Staudinger-aza-Wittig tandem reaction selectively affords in one step a monocellobiosyl[bis(ureido)]diazacrown cryptand and a bis(cellobiosyl)tetraureido[bis(diazacrown)] cryptand. Formation of each type of cryptand was under control by Na + or Cs + template effect.

Synthesis of new saccharide azacrown cryptands

“…Considering the synthesis of 21, it should be noticed that the cyclisation reaction can give two different macrocycles: one with the two disaccharides in an antiparallel direction and the other one with the two disaccharides in a parallel direction. 9 On the basis of the NMR analysis it seemed that the cryptand contained parallel arrangement of carbohydrate units. In the 13 C NMR spectrum of 21 only single signal of C1 and C6 could be observed.…”

“…9 The hydroxyl groups of carbohydrate molecules (1a-1c) were protected by using acetic anhydride in pyridine. Treatment of compounds 2a-2c with 35 % solution of hydrogen bromide in acetic acid afforded the corresponding bromo derivatives 3a-c with α-anomeric selectivity.…”

Nitrogen-Containing Macrocycles Having a Carbohydrate Scaffold

“…1 Jurczak described the synthesis of the first sugar-based cryptands. 104 The required di-azides were prepared from 2,2 0 ,3,3 0 ,4 0 ,6,6 0 -hepta-O-acetyl-α-cellobiosyl bromide two subsequent nucleophilic additions of tetraoxadiazacyclooctadecane (151), provided a macrocycle, the size of which was dependent on the metal cation template. 102 Marsura et al have developed an efficient and rapid method for the preparation of a family of macrobicyclic and macrotricyclic cryptands containing a carbohydrate subunit.…”

Convenient Synthesis of a Galacturonic Acid Based Macrocycle with Potential Copper‐Complexation Ability

“…[4] In connection with this approach, the exploitation of sugarbased macrocycles as receptors for cations has recently emerged. The preparation of new cryptands scaffolded onto d-glucose, [5] cellobiose, [6] sucrose [7] or d-ribose [8] has been reported as well as their complexation ability towards cations.…”