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|Title:||Investigations on photochemical linking of steroids with amino acids: Irradiation of α, β-unsaturated steroidal ketones in the presence of amino acids in aqueous medium|
|Authors:||Ishar, M P S|
Girdhar, N K
|Abstract:||Irradiation of 1, 4-cholestadien-3-one 1 in THF-H2O solvent in the presence of amino acids (glycine/alanine) leads to dienone-phenol photo rearrangement products, 3-hydroxy-l-methyl-19-norcholesta-1, 3, 5 (10) -triene 3 (35%), 4-hydroxy- 2-methyl-19-nor-cholesta-1, 3, 5 (10) -triene 4 (15%), 1-hydroxy-4-methyl-19-norcholesta-1, 3, 5 (10)-triene 5 (28%) along with a novel methyl substituted-19-norcholesta-1, 3, 5 (10)-triene 6 and a spirocyclic-enone 7; no amino acid or solvent addition product is obtained. Irradiation of 16-dehydropregnenolone-3β-acetate 2 under identical conditions in the presence of glycine affords the pregnenolone-3β -acetate 9 (25%), 16-(tetrahydrofuran-2-yl) -pregnenolone-3β-acetate 10 and its 17- α-isomer 11 (together 35%) and 16-(glycin-2-yl) -pregnenolone-3β-acetate 12 (mixture of isomers, 25%). The results are compared and contrasted with known photochemical behaviour of steroidal enones and dienones. The studies indicate that steroidal-16-ene-20-ones can be better photoaffinity labelling agents for progestogen and possibly, adrenal steroidal receptors. Also, the photochemical additions to ∆16-20-one steroidal systems can be exploited for the introduction of substituents/moieties at C16 in steroids.|
|Appears in Collections:||IJC-B Vol.38B(11) [November 1999]|
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