Dissemin is shutting down on January 1st, 2025

Published in

Wiley, European Journal of Organic Chemistry, 22(2006), p. 5135-5151, 2006

DOI: 10.1002/ejoc.200600591

Wiley-VCH Verlag, ChemInform, 6(38), 2007

DOI: 10.1002/chin.200706106

Links

Tools

Export citation

Search in Google Scholar

The Preparation and Absolute Configurations of Enantiomerically PureC4-Symmetric Tetraalkoxyresorcin[4]arenes Obtained from Camphorsulfonate Derivatives

This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

The preparation of a series of diastereoisomeric tetracamphorsulfonates derived from racemic tetramethoxyresorcin[4]arenes was achieved by reactions with an excess of (S)-(+)-10-camphorsulfonyl chloride in pyridine followed by isolation using flash chromatography. Tetradeprotonation of a number of tetramethoxyresorcin[4]arenes using n-butyllithium in tetrahydrofuran, followed by reactions using (S)-(+)-10-camphorsulfonyl chloride, gave the same tetracamphorsulfonates. Mono-, di- and tricamphorsulfonates were also prepared following selective deprotonation. In the reactions with tetraisopropyloxy- and tetracyclopentyloxyresorcin[4]arenes, only the mono- and dicamphorsulfonates were formed. X-ray crystallographic analysis established the absolute configurations of three diastereoisomerically pure tetracamphorsulfonates, including a diastereoisomer prepared from 6,12,18,24-tetramethoxy-2,8,14,20-tetrakis(2-methylpropyl) resorcin[4]arene. An additional pair of diastereoisomers was also prepared using (R)-(?)-10-camphorsulfonyl chloride and 6,12,18,24-tetramethoxy-2,8,14,20-tetrakis(2-methylpropyl)resorcin[4]arene, for one of which the structure was confirmed by an additional X-ray structure determination.Hydrolytic removal of the camphorsulfonyl residue(s) from the various diastereoisomers gave enantiomers ofknown absolute configurations. In some cases, the chiral nonracemic tetraalkoxyresorcin[4]arenes were converted into known tetrabenzoxazine derivatives by using N,N-bis(methoxymethyl)[(S)-(?)-(a-methylbenzyl)]amine in thermal or microwave-assisted reactions.