Phosphoric acid isomerization of A 5 (10), 9...

Details Phosphoric acid isomerization of A 5 (10), 9... Phosphoric acid isomerization of A 5 (10), 9...

2002-12-10

2004-09-28

Badio, Barbara P. (Department: 1616)

Organic compounds -- part of the class 532-570 series

Organic compounds

Cyclopentanohydrophenanthrene ring system containing

C552S648000

Reexamination Certificate

active

06797834

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is a chemical process for the isomerization of the &Dgr;
5(10),9(11)
-double bonds in a steroid to the corresponding &Dgr;
4,9
-isomer.
2. Description of the Related Art
J. Am. Chem. Soc
., 73, 4133 (1951) discloses isomerization of a &Dgr;
8(9)
-12-one steroid to the corresponding &Dgr;
9(11)
-12-one steroid using hydrochloric acid in methanol.
J. Chem. Soc
., 367 (1950) discloses isomerization of &Dgr;
5(10)
-3-one steroid to the corresponding &Dgr;
4(5)
-3-one steroid using sodium ethoxide.
Tetrahedron
, 22, 2837 (1966) discloses isomerization of a &Dgr;
5(10)
-3-one steroid to the corresponding &Dgr;
4(5)
-3-one steroid using potassium hydroxide in ethanol.
U.S. Pat. No. 3,052,672 discloses isomerization of &Dgr;
5(10),9(11)
-3-one steroid to the corresponding &Dgr;
4(5),9(10)
-3-one steroid using perchloric acid in acetic acid.
These documents while disclosing isomerization of double bonds leading to conjugation with the carbonyl group in six-membered rings in steroidal compounds do not use a phosphorous containing acid.
SUMMARY OF INVENTION
Disclosed is a process for the preparation of a &Dgr;
4,9
-steroid of formula (II)
where R
17
is:
(1) ═O;
(2) &agr;-R
17-1
:&bgr;-R
17-2
where one of R
17-1
and R
17-2
is:
(a) —OH,
(b) —O—Si(R
17-2a
)
3
where R
17-2a
are the same or different and are C
1
-C
6
alkyl or phenyl,
(c) —O—CO—R
17-2b
where R
17-2b
is:
(i) C
1
-C
6
alkyl,
(ii) phenyl,
(d) —O—R
17-2b
where R
17-2b
is as defined above, and the other of R
17-1
and R
17-2
is —H; which comprises
(1) contacting a &Dgr;
5(10),9(11)
-steroid of formula (I)
where R
17
is as defined above, with a phosphorous containing acid selected from the group consisting of phosphoric acid, polyphosphoric acid, metapahosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, tetrametaphosphoric acid, hypophosphoric acid, orthophosphoric acid or an acid containing phosphorus which is generated in situ.


REFERENCES:
patent: 3052672 (1962-09-01), Nomine et al.
K. K. Pivnitsky, N. N. Gaidamovich, and I. V. Torgov, “Configuration and Properties of DL-&Dgr;4,9-19-Nor-D-Homoandrostadiene-14&agr;-OL-3,17A-Dione”,Tetrahedron, vol. 22, 1966, pp. 2837-2844.
Louis F. Fieser and Srinivasa Rajagopalan, Evelyn Wilson and Max Tishler, “The Conversion of Cholic Acid into 3&agr;-Hydroxy-12-keto&Dgr;9(11)-cholenic Acid”,Chemical Laboratory of Harvard University and the Research Laboratories of Merck & Co., Inc., Sep. 1951, pp. 4133-4135.
Arthur J. Birch, “Hydroaromatic Steroid Hormones. Part I. 10-Nortestosterone”,The University Chemical Laboratory, No. 80, 1950, pp. 367-368.

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