Martin A Iglesias-arteaga | UNAM Universidad Nacional Autónoma de México (original) (raw)

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Papers by Martin A Iglesias-arteaga

The synthesis and spectroscopic characterization of a new bioactive steroid with bisnorcholanic 2... more The synthesis and spectroscopic characterization of a new bioactive steroid with bisnorcholanic 22!16 lactone moiety are described.

Treatment of different steroidal and aliphatic alcohols with BF 3. OEt 2 and acetic anhydride for... more Treatment of different steroidal and aliphatic alcohols with BF 3. OEt 2 and acetic anhydride for 5 seconds produced complete acetylation in high to quantitative yields.

Two simple Wittig procedures for the synthesis of (Z)-5-decenol and (Z)-5-decenyl acetate based o... more Two simple Wittig procedures for the synthesis of (Z)-5-decenol and (Z)-5-decenyl acetate based on the monoacetylation or monobromi-nation of 1,5-pentanediol were followed.

The reaction of steroid sapogenins of both the 25R and 25S series with diacetoxyiodobenzene and B... more The reaction of steroid sapogenins of both the 25R and 25S series with diacetoxyiodobenzene and BF 3 AEEt 2 O in formic acid produced a mixture of an equatorial 23-formyloxysapogenin, a 16b,23:23,26-diepoxy-22-one and a bisnorcholanic lactone. The outcome of this reaction, that drastically differs from the same reaction in acetic acid, opens up new possibilities for the transformation of the side chain of steroid sapogenins.

Treatment of steroid sapogenins with diacetoxyiodobenzene (DIB) and boron trifluoride ethyl ether... more Treatment of steroid sapogenins with diacetoxyiodobenzene (DIB) and boron trifluoride ethyl etherate in acetic acid led to the introduction of an axial acetoxyl group at position C-23 of the side chain.

Spirostane sapogenins have served for a long time as starting materials for the synthesis of diff... more Spirostane sapogenins have served for a long time as starting materials for the synthesis of different steroidal drugs . Recently, the sapogenins have been used in the synthesis of brassinosteroids [2] and cephalostatins . All synthetic procedures rely on the degradation or modification of the spiroketal moiet. The chemistry of spirostanes has been intensively studied during the mid part of the last century. However, the discovery of new natural products of interesting biological profile (such as cephalostatins) has stimulated further progress in the field.

The synthesis and characterisation of the naturally occurring steroid sapogenin laxogenin 1 and i... more The synthesis and characterisation of the naturally occurring steroid sapogenin laxogenin 1 and its derivatives 23-ketolaxogenin 10 and (23S)-hydroxylaxogenin 13 are described. Compounds reported have shown plantgrowth-stimulating activity in in vitro tests and in field trials.

Palladium catalyzed cross coupling between 3b-acetoxy-bisnorchol-5-en-22-oic acid and phenylboron... more Palladium catalyzed cross coupling between 3b-acetoxy-bisnorchol-5-en-22-oic acid and phenylboronic acid produced the hereto unknown 22-phenyl-3b-acetoxybisnorchol-5-en-22-one which crystallizes in the monoclinic system with space group P2 1 . The presence of 17bsubstituent that bears both the C21 methyl group and the introduced phenylketone moiety provides a twisted conformation on C13-C14 for the D ring with asymmetry parameters Altona et al., Tetrahedron 24:13-32, 1968): D = 711.4, s m = 47.3 (2), DC 2 (C13-C14) = 5.7 (3), DC s (C13) = 14.0 (3) and DC s (C14) = 21.6 (3)°. The angle 77.20 (8)°between planes of the steroid-ABCD framework and phenyl ring evidences the relative orthogonal positions of these fragments. The 1 H and 13 C NMR characterization of the obtained compound are described.

The naturally occurring dinorcholanic lactone vespertilin and two other non-natural derivatives b... more The naturally occurring dinorcholanic lactone vespertilin and two other non-natural derivatives bearing the 5␣-hydroxy-6-oxo moiety were synthesized starting from the readily available steroid sapogenin diosgenin. The obtained compounds showed plant growth promoting activity in the bean's second internode elongation assay.

A study of the reactivity of 25R and 25S 23E-benzylidene spirostanes that includes epoxidation, c... more A study of the reactivity of 25R and 25S 23E-benzylidene spirostanes that includes epoxidation, catalytic hy-drogenation as well as Lewis or Brønsted acid-catalyzed rearrangements is described. Exhaustive NMR characterization of the obtained compounds is presented. Additionally the structures of some of the obtained compounds were confirmed by single crystal X-Ray Diffraction studies.

The synthesis and spectroscopic characterization of a new bioactive steroid with bisnorcholanic 2... more The synthesis and spectroscopic characterization of a new bioactive steroid with bisnorcholanic 22!16 lactone moiety are described.

Treatment of different steroidal and aliphatic alcohols with BF 3. OEt 2 and acetic anhydride for... more Treatment of different steroidal and aliphatic alcohols with BF 3. OEt 2 and acetic anhydride for 5 seconds produced complete acetylation in high to quantitative yields.

Two simple Wittig procedures for the synthesis of (Z)-5-decenol and (Z)-5-decenyl acetate based o... more Two simple Wittig procedures for the synthesis of (Z)-5-decenol and (Z)-5-decenyl acetate based on the monoacetylation or monobromi-nation of 1,5-pentanediol were followed.

The reaction of steroid sapogenins of both the 25R and 25S series with diacetoxyiodobenzene and B... more The reaction of steroid sapogenins of both the 25R and 25S series with diacetoxyiodobenzene and BF 3 AEEt 2 O in formic acid produced a mixture of an equatorial 23-formyloxysapogenin, a 16b,23:23,26-diepoxy-22-one and a bisnorcholanic lactone. The outcome of this reaction, that drastically differs from the same reaction in acetic acid, opens up new possibilities for the transformation of the side chain of steroid sapogenins.

Treatment of steroid sapogenins with diacetoxyiodobenzene (DIB) and boron trifluoride ethyl ether... more Treatment of steroid sapogenins with diacetoxyiodobenzene (DIB) and boron trifluoride ethyl etherate in acetic acid led to the introduction of an axial acetoxyl group at position C-23 of the side chain.

Spirostane sapogenins have served for a long time as starting materials for the synthesis of diff... more Spirostane sapogenins have served for a long time as starting materials for the synthesis of different steroidal drugs . Recently, the sapogenins have been used in the synthesis of brassinosteroids [2] and cephalostatins . All synthetic procedures rely on the degradation or modification of the spiroketal moiet. The chemistry of spirostanes has been intensively studied during the mid part of the last century. However, the discovery of new natural products of interesting biological profile (such as cephalostatins) has stimulated further progress in the field.

The synthesis and characterisation of the naturally occurring steroid sapogenin laxogenin 1 and i... more The synthesis and characterisation of the naturally occurring steroid sapogenin laxogenin 1 and its derivatives 23-ketolaxogenin 10 and (23S)-hydroxylaxogenin 13 are described. Compounds reported have shown plantgrowth-stimulating activity in in vitro tests and in field trials.

Palladium catalyzed cross coupling between 3b-acetoxy-bisnorchol-5-en-22-oic acid and phenylboron... more Palladium catalyzed cross coupling between 3b-acetoxy-bisnorchol-5-en-22-oic acid and phenylboronic acid produced the hereto unknown 22-phenyl-3b-acetoxybisnorchol-5-en-22-one which crystallizes in the monoclinic system with space group P2 1 . The presence of 17bsubstituent that bears both the C21 methyl group and the introduced phenylketone moiety provides a twisted conformation on C13-C14 for the D ring with asymmetry parameters Altona et al., Tetrahedron 24:13-32, 1968): D = 711.4, s m = 47.3 (2), DC 2 (C13-C14) = 5.7 (3), DC s (C13) = 14.0 (3) and DC s (C14) = 21.6 (3)°. The angle 77.20 (8)°between planes of the steroid-ABCD framework and phenyl ring evidences the relative orthogonal positions of these fragments. The 1 H and 13 C NMR characterization of the obtained compound are described.

The naturally occurring dinorcholanic lactone vespertilin and two other non-natural derivatives b... more The naturally occurring dinorcholanic lactone vespertilin and two other non-natural derivatives bearing the 5␣-hydroxy-6-oxo moiety were synthesized starting from the readily available steroid sapogenin diosgenin. The obtained compounds showed plant growth promoting activity in the bean's second internode elongation assay.

A study of the reactivity of 25R and 25S 23E-benzylidene spirostanes that includes epoxidation, c... more A study of the reactivity of 25R and 25S 23E-benzylidene spirostanes that includes epoxidation, catalytic hy-drogenation as well as Lewis or Brønsted acid-catalyzed rearrangements is described. Exhaustive NMR characterization of the obtained compounds is presented. Additionally the structures of some of the obtained compounds were confirmed by single crystal X-Ray Diffraction studies.