Question

Chemical methods for determination of active methoxy group

Answer 1

Recent developments in methods for the deter- mination of enantiomeric composition (optical purity) have been reviewed by Mislow and Rabam2 … The Journal of Organic Chemistry … NMR CHEMICALSHlPTS OF bXASTEREOMERIC BSTERS AND AMIDES OF ( f )-a-METHOXY-a 


DETERMINATION OF THE METHOXY-GROU P CONTENT
OF INSOLUBLE ORGANIC SUBSTANCES OF SEDIMENTS
M. BALOGI an d M. VADKERTI TOTH
INTRODUCTION
A major part of geochemical investigations carried out in connection with
hydrocarbon occurrences aimed to decide whether the sediment is either a source
rock of hydrocarbons or perhaps it is merely a resevoir-rock where the hydrocarbons
accumulated by migration.
However, so far investigations of the identification of source-rocks have not
yielded exact results. [MACOVEI, 1928; TRASK, 1932; TRASK and PATNODE, 1942;
PHILIPPI, 1957; BRENNEMAN and SMITH, 1958; KALIFEH and Louis, 1961; BREGER
and BROWN, 1962; HEDBERG, 1964; BRAY and EVANS, 1965. — cited by NAGY, B.
a n d U. COLOMBO, 1967.]
Relying upon results obtained through experiments of investigators referred to,
COLOMBO [1967] stated that practically it is impossible to draw a well defined line
between hypothetical source-rocks and no-source ones. This statement means that
all sedimentary rocks more or less contribute to the generation of hydrocarbons,
which at last are accumulated in the reservoir rocks.
To decide to what extent had the organic matter coming from a given area
contributed to the formation of hydrocarbons found there, very important data may
be yielded by a complex study of kerogen, the insoluble organic material of sediments.
FORSMAN and HUNT [1958] differentiate three types of kerogens isolated from
sediments coming from different localities. They classify coaly-, non-coaly oil shaleand coaly oil shale-types.
Coaly-type kerogens are very markedly similar to substances found in peat,
lignite and other coals; they mostly consist of lignin-like compounds. These kerogens
can be regarded as built up of macromolecules consisting of condensed aromatic
rings, wherein the rings are connected by ether-, alkoxi- and sulphuric bridges, respectively. Hydroxyl-, methoxy- and sometimes esterified carboxyl-groups may be
connected with the aromatic core.
Non-coaly oil shale kerogens are characterized by straight-chain structures,
with little cycloparaffin and an aromatic ring with one core, connected with a functional group with less oxygen content.
Coaly oil shale kerogens, as regarding their properties represent a transition
between kerogens classified in the former two types.
It has been pointed out that from the point of view of the formation of hydrocarbons sediments containing non-coaly oil shale kerogens are the most important.
A number of experiments have been carried out to classify kerogens of sediments of different hydrocarbon occurrences according to the former classification.

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