Cereal grain resorcinolic lipids: mono and dienoic homologues are present in rye grains
摘要:
Analyses (UV, IR, H-1-NMR, MS) of the main phenolic fractions isolated by sequential separation on normal-phase and by argentation chromatography on silica gel confirmed the presence of monoenoic and dienoic homologues of 1,3-dihydroxy-5-n-alkylbenzene in acetone extracts from rye grains. Conversion of mono and dienoic homologue dimethyl ethers to the cis-diols with osmium tetroxide, transformation of the diol to the acetonide with acetone and subsequent MS analysis of resulting derivatives showed that the breakdown pattern for the monoenoic homologues was consistent with a double bond in all the homologous chain length at the 8-position. For dienes, the results were not so conclusive, although the 8- and 11-positions appear to be the favoured ones. It has been also shown that rye 5-n-ketoalkylresorcinols contain a previously unobserved C17 homologue. All identifications were confirmed by comparison with synthetically obtained C19:0 and C21:0 5-n-alkylresorcinols and a 5-n-(2-keto-heptadecyl)resorcinol. Other minor phenolic components present in the acetone extract were identified as homologous 5-n-(2-hydroxyalkyl)resorcinols.
Soluble, highly conjugated derivatives of polyacetylene from the ring-opening metathesis polymerization of monosubstituted cyclooctatetraenes: synthesis and the relationship between polymer structure and physical properties
作者:Christopher B. Gorman、Eric J. Ginsburg、Robert H. Grubbs
DOI:10.1021/ja00057a024
日期:1993.2
Abstract : Using well-defined tungsten-based olefinmetathesis catalysts, a family of partially substituted polyacetylenes have been synthesized via the ring-opening metathesis polymerization (ROMP) of monosubstituted cyclooctatetraenes (RCOT). These polymers are highly conjugated as evidenced by their visible absorption maxima, they are of high molecular weight as evidenced by gel permeation chromatography