SELENIUM DEHYDROGENATION OF CHOLESTEROL, CHOLESTANE AND OPTICALLY ACTIVE PETROLEUM FRACTIONS

46 Pages·01.989 MB·English

by  FALL, HARRY H

THE PENNSYLVANIA STATE COLLEGE
The Graduate School
Department of Chemistry
SELENIUM DEHYDROGENATION OF CHOLESTEROL, CHOLESTANE
AND OPTICALLY ACTIVE PETROLEUM FRACTIONS
A D issertatio n
by
HARRY H« FALL
Subm itted in P a rtia l F ulfillm ent of the
Requirements for the Degree of,
Doctor of Philosophy
September 195>0
A ssociate P rofessorial Orgaiic^ Chemistry
Head of Department of Chemistry
ACKNOWLEDGMENTS
The author -thanks Dr* Thomas S. Oakwood for his suggestion of
the problem and far h is unbounded enthusiasm , unfailing encouragement
and invaluable advice throughout the course of th is investigation*
Acknowledgment is also made of the fin an cial support of th is pro ject
by the American Petroleum In stitu te*
TABLE OF CONTENTS
Page
INTRODUCTION 1
HISTORICAL 2
EXPERIMENTAL 7
I . DESCRIPTION OF EQUIPMENT 7
I I . DEHYDRQGENATION OF CHOLESTEROL 9
H I. DEHYDROGENATION OF CHOLESTANE 13
17. DEHXDROGENATION OF LUBRICANT FRACTION FRC8I GULF 22
COAST CRUDE (TEXAS CROWN) OIL
DISCUSSION 2?
X. DEHYDROGENATION OF CHOLESTEROL 27
I I . DEHYDROGENATION OF CHOLESTANE 29
III# DEHffROGENATION OF TEXAS CROWN OIL 30
SUMMARY 1*0
BIBLIOGRAFHY 1*2
INTRODUCTION
The o p tical a ctiv ity of petroleum has long been a sig n ifican t
fact* The only knowledge available concerning the specific molecules
in petroleum possessing o p tical ro tatio n is the m olecular weight
range in which th is property occurs and the great sta b ility of the
molecules*
Other work in th is laboratory has shown the means of obtaining
highly ro tato ry fractio n s, whose properties indicate th at the activ ity
is most lik e ly due to hydrocarbons containing 28 to 30 carbon atoms
and 50 to hydrogen atoms and having at le a st 3 non-aromatic rings*
Selenium dehydrogenation has been used extensively and success­
fu lly in determ ining the structures of biologically derived chemicals
and also in obtaining the arom atic counterparts of naphthenic hydro­
carbons* These were the reasons for the selection of th is method to
seek the structure of the optically active molecule or molecules in
petroleum*
The investigation was planned in three phases. C holesterol was
dehydrogenated to estab lish a procedure for the obtaining of hydro­
carbons known to be among the products of th is reaction. Then,
cholestane was dehydrogenated to determine the effect of selenium
dehydrogenation on saturated hydrocarbons of stero id al character*
And fin a lly , those fractions of o il with high o p tical ro tatio n were
dehydrogenated to learn i f the products could be stru ctu rally related
to those of the previous two phases*
HISTORICAL
In 1927> D iels, Gttdke and Kfirding (1) dehydrogenated cholesterol
w ith selenium in an attem pt to estab lish the structure of th is ste ro l
by characterizing the products of the reaction. Two hydrocarbons
were obtained: C^gH^, m*P* 128°-129°, and C25H2l|> 220°.
Bergmann and Hillemann (2,3) d efin itely established the structure of
CJ 18^16* hereafter called "D iels' Hydrocarbon", by the f ir s t synthesis
as 3t"»ethyl—1, 2-cyclopentenophenanthrene (i):
I
Although Cook and coworkers (U) have sought to id en tify conclusively
the CpgHpjj hydrocarbon, th e ir evidence only re la te s the stru ctu re of
of the compound to th a t of 2 ', -naphtha- , 2-fluorene (II) (!*,£)•
1 1 1
II
The im portance of the id e n tific a tio n of D iels' Hydrocarbon as
’ -m ethyl- , -cyclopentenophenanthrene lie s in the fact th at the
3 1 2
selenium dehydrogenation of stero id s, p articu larly ste ro ls, b ile acids
and cardiac aglucones (6) leads to its form ation. Thus D iels’ Hydro­
carbon was id en tified as the selenium dehydrogenation product of
cholesterol (1, 7,8,9,10), ergosterol (7,8, 9,10), cholesteryl chloride
(1, 11), cholic acid (7, 8, 9,12), sarsasapogenin (13), gitogenin (13,lU),
digitoxigenin (lh) , gitoxigenin (li|), strophanthidin (lh ,lf?,l6),
peristogenin (lU), uzarigenin (lU), p arilleg in (lU), dihydrolum isterol
acetate (17), and 5-androstenediol (18). Furthermore, Eutenandt and
Suranyi (18) found th at selenium dehydrogenation converted the follow­
ing stero id hormones into methyl isomers and derivatives of D iels’
Hydrocarbon: 3-acetate of 6-m ethylandrostane-3,5-diol yielded 9-
methylcyclopentenophenanthrene, 6-m ethylandrostane-3,5, 17-trio l
yielded 31 , 9-dim ethylcyclopentenophenanthrene, and 2, 6,17-dime th y l-
androstene-6,17-d io l yielded 3* ,3* , 9-trim ethylcyclopentenophenan-
threne.
Dehydrogenation of cholesterol and ergosterol w ith selenium
leads to the form ation of the 025^21}. hydrocarbon (1,5,7,8,9,10,11,
19,20). In addition, both D iels (1) and Cook (11) obtained C25**2l4.
by the dehydrogenation of cholesteryl chloride.
As previously noted, the id en tity of D iels' Hydrocarbon w ith
31 -m ethyl-1, 2-cyclopentenophenanthrene was established by the synthesis
of the la tte r and comparison w ith the D iels’ Hydrocarbon obtained by
selenium dehydrogenation. In itia lly , Cook and Hewett (11,21)
considered D iels1 Hydrocarbon as 1, 2-cyclopentenophenanthrene and
prepared th a t compound, m.p. 13i4°—135°* Along th is lin e , Ruzicka and
coworkers (22) synthesized the 1'- and 2' -m ethyl isom ers and the
parent compound. Since the l 1-m ethyl m elted 76°-77° and the 21 -m ethyl
m elted 106.5°-i07° * and since, in addition, m ixtures of the TNB's
(trinitroloenzene complex) w ith th at of D iels1 Hydrocarbon depressed
the m elting p o in t, these were elim inated from consideration. On the
other hand, the p ro p erties of D iels' Hydrocarbon and the parent
hydrocarbon were sim ilar as Table I dem onstrates.
Table I
CisH ^from Synthetic
C holesterol c17HlU Mixed
Hydrocarbon 12U°-125° 13U°-135° 130°-131°
P icrate 117°-118* 133°-13U° 12U°-126°
TNB 150°-151° 165°-166° 150°- 1510
U ltrav io let Spectra (21) — Maxima
From C holesterol 2167 258U 2795 2887 3007 3209 3559 3518
S ynthetic 2165 2586 2798 2883 3007 3211 3360 3518
The f ir s t synthesis of D iels' Hydrocarbon was done by Bergmann and
Hillemann (2) according to the follow ing scheme:
0
- c-ch3
a 9 +Zn+BrCH2C00CH3 -------> C^H ?C(CH3) « CHC00CH3
— ----> C1^H^CH(CH3)CHgC00CH3 — > C1^H?CH(GH3)CH2C00H
5.
CUCVAo,
CV \ C .^ 3
SOClo
,CH*
AlCl^*
0 m.p. 126°-127°
w hite needles
Kon (23) prepared the compound by condensation of (b —(o^ —naphthyl-
ethyl)-m agnesium bromide w ith 2 ,$-dim ethylcyclopentanone follow ed by
dehydration w ith phosphorus pent oxide and dehydrogenation of the
cyclic product m th selenium . The synthesized compound and its p ic-
ra te and TNB were indistinguishable from D iels’ Hydrocarbon.
The unequivocal id e n tific a tio n of th is compound was made d iffic u lt
by two p o in ts. F irs t, the method of mixed m elting points is known to
be unreliable in th is series of compounds (11,22,2^,2$). And,
secondly, the u ltra v io le t spectra are not d issim ilar. Thus, w hile
Kon (23) found appreciable differences in the spectra of D iels’
Hydrocarbon and 1,2-cyclopentenophenanthrene, Cook and Hewett (21),
on the other hand, found th at they were extrem ely alik e. In fa c t,
the author found th at Kon's curves for D iels' Hydrocarbon obtained
from cholesterol and from ergosterol also had ’’appreciable d ifferen ces”.
Ruzicka and Peyer (12) noted th at cholestane was obtained by the
m ild dehydrogenation of ch o lestero l. U nfortunately, although the
experiment was to be published a t a la te r date, a careful search
through the H elvetica Chimica A cta, in which Ruziclca usually published,
and Chemical A bstracts failed to reveal such a paper. However, Doree
and Petrow (26) did obtain cholestane by heating ch o lesterilen e,
CPyH)|)t> w ith selenium for 155 hours a t 230°— 250°•
Whether chrysene (III) is a product of the selenium dehydro-
I I I
genation of ch o lestero l rem ains a moot question. In 1925, D iels
and G^dke (27) heated ch o lestero l w ith palladium charcoal and
obtained an arom atic hydrocarbon* m.p, 250° and mol, wt. 220, which
they la te r id e n tifie d as chrysene (28). D iels and K arstens (7)
found th a t chrysene was the dehydrogenation product of cholic acid
w ith selenium . Ruzicka and coworkers (8 ,9 ,1 2 ), on the other hand,
could find no chrysene. In a review on the subject by L instead (29)
th is difference was attrib u te d to the higher tem peratures used by
D iels as Ruzicka and Peyer (12) did find a sm all amount of chrysene
when cholic acid was dehydrogenated a t 1+20°• D espite th is, n eith er
school could find any chrysene in the products resu ltin g from the
selenium dehydrogenation of ch o lestero l.
EXPERIMENTAL
I . DESCRIPTION OF EQUIPMENT
1* APPARATUS FOR DEHYDROGENATION
Since the fumes of hydrogen selenide, resulting from a ll the
dehydrogenations done in th is th esis, are unpleasant and poisonous,
the apparatus fo r the dehydrogenations was designed to remove them*
I t consisted of two sections: the reaction section in which the
dehydrogenation occurred and the pertinent products remained, and the
trap section in which the hydrogen selenide was p recip itated as
copper selenide*
The reaction section was composed of a reaction flask and a
reflu x condenser* The reaction flask was a 200 ml* round bottom
flask w ith an elongated neck term inating in a male ground glass joint*
A mercury seal was added to prevent any losses caused by the pressures
the gaseous products generated. The over-all length was 2h cm*, and
the in te rn a l diam eter of the neck was 20 mm* The condenser was 29 cm.
long and 20 mm. in in te rn al diam eter; both ends were female ground
glass joints*
Three 1-1* round bottom flasks in series made up the trap sec­
tio n . Each had two necks: one, in the center of the flask , provided
an in le t fo r the reaction gases and the second, to the side, provided
the o u tle t. The la s t two flasks of the sequence contained 500 ml. of