Abstract
The synthesis of N -Boc-diaza-21-crown-7 (4 ) is described. Bis-Boc-protected 1,8-diamino-3,6-dioxaoctane (2 ) was treated with 1,11-diiodo-3,6,9-trioxaundecane to form N ,N ′-bis-Boc-diaza-21-crown-7 (3 ) in moderate yield. Treatment of the bis-Boc-protected crown with trifluoroacetic
acid resulted in isolation of the desired mono-N -Boc-diaza-21-crown-7 (4 ) with none of the expected diaza-21-crown-7.
Key words
diaza-21-crown-7 - unsymmetrical functionalization - Boc group
References <A NAME="RS10201ST-1">1 </A>
Present address: Department of Chemistry, University of Florida, P. O. Box 117200,
Gainesville, FL 32611-7200.
<A NAME="RS10201ST-2">2 </A>
Gokel GW.
Crown Ethers and Cryptands
Royal Society of Chemistry;
Cambridge:
1994. ; and references cited therein
<A NAME="RS10201ST-3">3 </A>
Krakowiak K.
Bradshaw JS.
Zamecka-Krakowiak DJ.
Chem. Rev.
1989,
89:
929
<A NAME="RS10201ST-4">4 </A>
Kirkovits GJ.
Hall CD.
Advances in Supramolecular Chemistry
Vol. 7:
Gokel GW.
JAI;
Greenwich, CT:
2000.
p.1 ; and references cited therein
<A NAME="RS10201ST-5">5 </A>
Hall CD.
Kirkovits GJ.
Hall AC.
Chem. Commun.
1999,
1897
<A NAME="RS10201ST-6">6 </A>
Kulstad S.
Malmsten LÅ.
Acta Chem. Scand. B
1979,
33:
469
<A NAME="RS10201ST-7">7 </A>
Krakowiak KE.
Maas GE.
Bradshaw JS.
Hathaway JK.
Izatt RM.
J. Heterocyclic Chem.
1995,
32:
179
<A NAME="RS10201ST-8">8 </A>
Krakowiak KE.
Bradshaw JS.
J. Heterocyclic Chem.
1995,
32:
1639
