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US 4,917,827 AGranted
Process for the preparation of 9(11)-dehydro steroids
AssigneeGist-Brocades N.V.
InventorsJacobus N. M. Batist, Nicolaas C. M. E. Barendse, Arthur F. Marx
Life of this patent
Estimating the term…
Abstract
9(11)-dehydroandrostanes and 9(11)-dehydropregnanes are prepared by dehydrating the corresponding 9-alpha-hydroxy steroid in the presence of a Lewis acid. The corresponding 8(9)-dehydro-isomer was not detectable. The resulting products are valuable intermediates in steroid synthesis especially in the preparation of corticosteroids.
Claims5
Process for preparing a 9(11)-dehydro steroid selected from the group consisting of androstane and pregnane series steroids, comprising
- providing a 9-alpha-hydroxy steroid selected from the group consisting of androstane and pregnane series steroids, said 9-alpha-hydroxy steroid having at least one hydrogen atom at the C-11 position;
- and
- dehydrating said 9-alpha-hydroxy steroid in an inert organic solvent in the presence of a Lewis acid thereby removing the 9-alpha-hydroxy group and the hydroxy atom at the C-11 position and producing the corresponding 9(11)-dehydro steroid.
Dependencies are inferred from the claim text.