ISSN:
0935-6304
Keywords:
n-Alkylthiophenes
;
Isoprenoid alkylthiophenes
;
Mass spectra
;
Kovats retention indices
;
Deep sea sediments
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Six isomeric C20 alkylthiophenes were synthesized in order to prove the occurrence of such compounds in various deep sea sediments. As expected from the analogy with the corresponding saturated hydrocarbons, 2- and 3-heptadecylthiophene have considerably longer relative retention times than the isomeric isoprenoid compounds, i.e. 2- and 3-(4,8,12-trimethyltridecyl)thiophene and 3- and 4-methyl-2-(3,7,11-trimethyldodecyl)thiophene. Covats retention indices for all compounds were determined by isothermal analysis at 190°C on two different silicone-coated capillary columns. The mass spectra of the monoalkylated thiophenes show a base peak at m/z 98 corresponding to a Mcafferty rearrangement product in the case of the 3-substituted isomers, whereas a simple benzylic cleavage dominates in the mass spectra of 2-alkylthiophenes. 4-Methyl-2-(3,7,11-trimethylodecy)thiophene is an exception from this simple rule because also shows the McLafferty rearrangement as dominant fragmentation. Two of the isoprenoid thiophenes are prominent compounds in various deep sea sediments.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jhrc.1240110905
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