Abstract
7,15,23-Tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix[3]arene (1H3) was tri-O-alkylated with alkyl halides (RX: R=Me, Et, n-Pr, and n-Bu) in the presence of various bases and the products (1R3) were analyzed by HPLC and 1H NMR spectroscopy. It was found that (i) ring inversion which occurs through the oxygen-through-the-annulus rotation is allowed for 1Me3, 1Et3, and 1Pr3 whereas it is inhibited for 1Bu3, (ii) the cone/partial-cone equilibrium in 1Et3 and 1Pr3 is predominantly inclined to partial-cone, indicating the thermodynamic stability of partial-cone conformers, and (iii) in the product distribution of 1Bu3 partial-cone is yielded in preference for cone, indicating the kinetic preference for partial-cone. From the analysis of the reaction intermediates the possible reaction routes to cone- and partial-cone-1Bu3 are discussed. 1R3 showed the selectivity toward K+ among alkali metal cations and the cone conformers had the extractability (Ex%) higher than the partial-cone conformers. Cone-1R3 showed the high affinity for BuNH3+ because of (averaged) C3 symmetry common to both cone-1R3 host and BuNH3+ guest.
| Original language | English |
|---|---|
| Pages (from-to) | 9465-9478 |
| Number of pages | 14 |
| Journal | Tetrahedron |
| Volume | 49 |
| Issue number | 42 |
| DOIs | |
| Publication status | Published - Jan 1 1993 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Biochemistry
- Drug Discovery
- Organic Chemistry
Cite this
Conformational isomerism in and binding properties to alkali-metals and an ammonium salt of O-alkylated homooxacalix[3]arenes. / Araki, Koji; Inada, Kousuke; Otsuka, Hideyuki; Shinkai, Seiji.
In: Tetrahedron, Vol. 49, No. 42, 01.01.1993, p. 9465-9478.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Conformational isomerism in and binding properties to alkali-metals and an ammonium salt of O-alkylated homooxacalix[3]arenes.
AU - Araki, Koji
AU - Inada, Kousuke
AU - Otsuka, Hideyuki
AU - Shinkai, Seiji
PY - 1993/1/1
Y1 - 1993/1/1
N2 - 7,15,23-Tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix[3]arene (1H3) was tri-O-alkylated with alkyl halides (RX: R=Me, Et, n-Pr, and n-Bu) in the presence of various bases and the products (1R3) were analyzed by HPLC and 1H NMR spectroscopy. It was found that (i) ring inversion which occurs through the oxygen-through-the-annulus rotation is allowed for 1Me3, 1Et3, and 1Pr3 whereas it is inhibited for 1Bu3, (ii) the cone/partial-cone equilibrium in 1Et3 and 1Pr3 is predominantly inclined to partial-cone, indicating the thermodynamic stability of partial-cone conformers, and (iii) in the product distribution of 1Bu3 partial-cone is yielded in preference for cone, indicating the kinetic preference for partial-cone. From the analysis of the reaction intermediates the possible reaction routes to cone- and partial-cone-1Bu3 are discussed. 1R3 showed the selectivity toward K+ among alkali metal cations and the cone conformers had the extractability (Ex%) higher than the partial-cone conformers. Cone-1R3 showed the high affinity for BuNH3+ because of (averaged) C3 symmetry common to both cone-1R3 host and BuNH3+ guest.
AB - 7,15,23-Tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix[3]arene (1H3) was tri-O-alkylated with alkyl halides (RX: R=Me, Et, n-Pr, and n-Bu) in the presence of various bases and the products (1R3) were analyzed by HPLC and 1H NMR spectroscopy. It was found that (i) ring inversion which occurs through the oxygen-through-the-annulus rotation is allowed for 1Me3, 1Et3, and 1Pr3 whereas it is inhibited for 1Bu3, (ii) the cone/partial-cone equilibrium in 1Et3 and 1Pr3 is predominantly inclined to partial-cone, indicating the thermodynamic stability of partial-cone conformers, and (iii) in the product distribution of 1Bu3 partial-cone is yielded in preference for cone, indicating the kinetic preference for partial-cone. From the analysis of the reaction intermediates the possible reaction routes to cone- and partial-cone-1Bu3 are discussed. 1R3 showed the selectivity toward K+ among alkali metal cations and the cone conformers had the extractability (Ex%) higher than the partial-cone conformers. Cone-1R3 showed the high affinity for BuNH3+ because of (averaged) C3 symmetry common to both cone-1R3 host and BuNH3+ guest.
UR - http://www.scopus.com/inward/record.url?scp=0027375960&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027375960&partnerID=8YFLogxK
U2 - 10.1016/S0040-4020(01)80216-7
DO - 10.1016/S0040-4020(01)80216-7
M3 - Article
AN - SCOPUS:0027375960
VL - 49
SP - 9465
EP - 9478
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 42
ER -