A folded conformation of an ascidiacyclamide derivative: 3-methoxysulfoxide-(2R,3R)-threoninyl desoxazoline-ascidiacyclamide

Citation
M. Doi et al., A folded conformation of an ascidiacyclamide derivative: 3-methoxysulfoxide-(2R,3R)-threoninyl desoxazoline-ascidiacyclamide, ACT CRYST E, 57, 2001, pp. O1019-O1021
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE
ISSN journal
1600-5368 → ACNP
Volume
57
Year of publication
2001
Part
11
Pages
O1019 - O1021
Database
ISI
SICI code
1600-5368(200111)57:<O1019:AFCOAA>2.0.ZU;2-G
Abstract
Ascidiacyclamide, cyclo(-Ile-Oxz-D-Val-Thz-)(2), has two methyl-oxazoline ( Oxz) residues, and each Oxz residue has two chiral C atoms. In the present work, C38H60N8O12S4, a chiral modification of these atoms was attempted. A total of ten diastereomers were considered, of which seven were synthesized . For the three remaining diastereomers, the reaction was incomplete or ver y much slowed down. These diastereomers had the D configuration for both Ox z residues. This result appeared to be related to the conformation of the r eaction intermediates. Therefore, the intermediates were converted into sta ble forms and then isolated to confirm their structures. Crystals were obta ined from one derivative and its structure was found to be of the folded fo rm. In this form, the activated atoms were separated from the target atoms. It is suggested that this folded conformation hinders the completion of th e reaction.