TY - JOUR
T1 - The preparation and absolute configurations of enantiomerically pure C4-symmetric tetraalkoxyresorcin[4]arenes obtained from camphorsulfonate derivatives
AU - Buckley, Benjamin R.
AU - Bulman Page, Philip C.
AU - Chan, Yohan
AU - Heaney, Harry
AU - Klaes, Michael
AU - McIldowie, Matthew J.
AU - McKee, Vickie
AU - Mattay, Jochen
AU - Mocerino, Mauro
AU - Moreno, Eduardo
AU - Skelton, Brian W.
AU - White, Allan H.
PY - 2006/11/13
Y1 - 2006/11/13
N2 - 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]are ne. 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]are ne, 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 of known 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. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.
AB - 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]are ne. 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]are ne, 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 of known 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. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.
KW - MITTEILUNG
KW - ACID
KW - RESORCINARENES
KW - CYCLODIASTEREOMERIE
KW - diastereoselectivity
KW - CHIRALITY
KW - CALIXARENES
KW - camphorsulfonates
KW - determination
KW - hydrolysis
KW - chiral auxiliaries
KW - BINAPHTHYL CROWN UNIT
KW - OPTICAL RESOLUTION
KW - CALIX<4>ARENES
KW - axial chirality
KW - CYCLOENANTIOMERIE
KW - Mannich reactions
KW - configuration
KW - resorcin[4]arenes
U2 - 10.1002/ejoc.200600591
DO - 10.1002/ejoc.200600591
M3 - Article
SN - 1434-193X
VL - 2006
SP - 5135
EP - 5151
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
IS - 22
ER -