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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2007-11-16
pubmed:abstractText
A full account of the synthesis of the 12 hexacyclic tetrahydrofuran isomers represented by the nearby formulas is first provided. The key steps involved in further elaboration of the spiro ethers 12, 15, 28, and 45 include controlled ozonolysis, 1,2-addition of the Normant reagent, and heterocyclization. Eight of the end products proved to be sufficiently crystalline to enable X-ray analysis and determination of their solid-state conformational features. The alkali metal ion selectivities of the 12 hexamers were evaluated by a picrate extraction method and by electrospray ionization mass spectrometry (ESI-MS) which indicated that small, but significant, selectivity differences exist within the groups of diastereomers. These results revealed that each hexamer demonstrated a preference for lithium ion complexation relative to sodium or potassium ion complexation. Stereoisomeric classification of the hexamers was based on the competition between two dissociation routes promoted by collision-induced dissociation. The preference for each of the two dissociation pathways, both of which involved cleavage at the midpoint of the hexamer, correlated with the stereochemical configurations (syn versus anti) of the THF groups near the termini.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3263
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9088-101
pubmed:year
2007
pubmed:articleTitle
X-ray crystallographic and mass spectrometric probing of the conformational and ionophoric properties of stereoisomeric hexatetrahydrofuranylhexane segments.
pubmed:affiliation
Evans Chemical Laboratories, The Ohio State University, Columbus, OH 43210, USA.
pubmed:publicationType
Journal Article