Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives

Conversion of 20-acetoxy-18-iodopregn-4-en-3-one 1 to the 18-iodosyl derivative by MCPBA resulted in a Wagner–Meerwein-type rearrangement with regioselective migration of the C13–C17 bond to give, in high yield, an abeo-pregnane in which C-18 was incorporated into ring D. The rearranged steroid was...

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Publicado: 2001
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14727781_v1_n13_p1511_Nicoletti
http://hdl.handle.net/20.500.12110/paper_14727781_v1_n13_p1511_Nicoletti
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spelling paper:paper_14727781_v1_n13_p1511_Nicoletti2023-06-08T16:17:25Z Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives Chemical bonds Crystal structure Fourier transform infrared spectroscopy Mass spectrometers Nuclear magnetic resonance spectroscopy Positive ions Stereochemistry X ray crystallography Regioselective migration Aromatic hydrocarbons Conversion of 20-acetoxy-18-iodopregn-4-en-3-one 1 to the 18-iodosyl derivative by MCPBA resulted in a Wagner–Meerwein-type rearrangement with regioselective migration of the C13–C17 bond to give, in high yield, an abeo-pregnane in which C-18 was incorporated into ring D. The rearranged steroid was epoxidized in situ yielding a mixture of β and α 13,14-epoxides (3 and 4) which were characterized spectroscopically and by X-ray crystallography. When (20R)-20-iodopregn-4-en-3-one 9 was used as substrate, regioselective migration of the C16–C17 bond gave the D-homoandrostane with incorporation of C-20 into ring D in up to 95% yield. The 20S epimer 9 however, gave a mixture of substitution and rearrangement products. The crystal structures of the deacetylated β-epoxide 3 (5), the methanolysis product of α-epoxide 4 (7) and 20-iodopregnanes 9 and 9 are reported. © 2001 The Royal Society of Chemistry. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14727781_v1_n13_p1511_Nicoletti http://hdl.handle.net/20.500.12110/paper_14727781_v1_n13_p1511_Nicoletti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Chemical bonds
Crystal structure
Fourier transform infrared spectroscopy
Mass spectrometers
Nuclear magnetic resonance spectroscopy
Positive ions
Stereochemistry
X ray crystallography
Regioselective migration
Aromatic hydrocarbons
spellingShingle Chemical bonds
Crystal structure
Fourier transform infrared spectroscopy
Mass spectrometers
Nuclear magnetic resonance spectroscopy
Positive ions
Stereochemistry
X ray crystallography
Regioselective migration
Aromatic hydrocarbons
Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
topic_facet Chemical bonds
Crystal structure
Fourier transform infrared spectroscopy
Mass spectrometers
Nuclear magnetic resonance spectroscopy
Positive ions
Stereochemistry
X ray crystallography
Regioselective migration
Aromatic hydrocarbons
description Conversion of 20-acetoxy-18-iodopregn-4-en-3-one 1 to the 18-iodosyl derivative by MCPBA resulted in a Wagner–Meerwein-type rearrangement with regioselective migration of the C13–C17 bond to give, in high yield, an abeo-pregnane in which C-18 was incorporated into ring D. The rearranged steroid was epoxidized in situ yielding a mixture of β and α 13,14-epoxides (3 and 4) which were characterized spectroscopically and by X-ray crystallography. When (20R)-20-iodopregn-4-en-3-one 9 was used as substrate, regioselective migration of the C16–C17 bond gave the D-homoandrostane with incorporation of C-20 into ring D in up to 95% yield. The 20S epimer 9 however, gave a mixture of substitution and rearrangement products. The crystal structures of the deacetylated β-epoxide 3 (5), the methanolysis product of α-epoxide 4 (7) and 20-iodopregnanes 9 and 9 are reported. © 2001 The Royal Society of Chemistry.
title Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
title_short Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
title_full Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
title_fullStr Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
title_full_unstemmed Rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
title_sort rearrangement of 18-iodo- and 20-iodopregnanes mediated by iodosyl derivatives
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14727781_v1_n13_p1511_Nicoletti
http://hdl.handle.net/20.500.12110/paper_14727781_v1_n13_p1511_Nicoletti
_version_ 1768543672653053952