Roxana Perez Gil

Synthesis of (22R, 25R)-3β,26-Dihydroxy-5α-furostan-6-one #

Abstract The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described. # Dedicated to Dr. Charles Descoins on the occasion of his 62nd birthday.

Spirostanic analogues of teasterone. Synthesis, characterisation and biological activity of laxogenin, (23S)-hydroxylaxogenin and 23-ketolaxogenin (23-oxolaxogenin)

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 plant-growth-stimulating activity in in vitro tests and in field trials.

Synthesis of (22R, 25R)-2α,3α,26-Trihydroxy-5α-furostan-6-one

Abstract The synthesis of a plant growth promoter furostanol which bears the charateristic functionality of castasterone on rings A and B is described.

Synthetic Steroidal Sapogenins. Part III1 23-Ketohecogenin and 23-Ketoisochiapagenin

Abstract The synthesis of the 23-keto analogues of the steroidal sapogenins hecogenin and isochiapagenin is described.

Synthesis of (25R)-5α-Spirostan-2α,3α,6β-triol Triacetate#

Abstract The synthesis of (25R)-5α-spirostan-2α,3α,6β-triol triacetate is presented. #Dedicated to Dr. Maria Dolores E. Lopez (Lita) in the occasion of her 99th birthday. †Present Address: Instituto de Productos Naturales y Agrobiologia, Apartado de Correos 195, Avda. Astrofisico F. Sanchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain.

Synthesis of Analogues of Brassinosteroids from Chenodeoxycholic Acid

The synthesis and spectroscopic characterization of two new bioactive analogues of brassinosteroids with a 24-hydroxylated cholanic side chain, an A/B ring cis-junction and oxygenated functions in C-7 is described.

13 C and 1H NMR Spectra of Synthetic (25R)-5α-Spirostanes

The assignment of 13C and 1H NMR signals of synthetic (25R)-5α-spirostanes is presented; the main effects on chemical shifts due to substitution at C-23 are briefly discussed.

(25R)-6β-Acetoxy-3β-bromo-5α-spirostan-23-one

In the title compound [systematic name: (25R)-3β-bromo-23-oxo-5α-spirostan-6-yl acetate, C 29 H 43 BrO 5 ], the C3-Br bond is oriented equatorially and (-)-antiperiplanar with respect to the C4-C5 bond. The six-membered B, C and F rings have chair conformations, as is usual in this type of compound. The five-membered D ring adopts a 14α-envelope conformation and the E ring adopts a C22β,O3α-half-chair conformation. The A/B, B/C and C/D ring junctions are trans.

Methyl 3β-Bromine-7α-hydroxy-5β-cholan-24-oate

In the title compound, C 25 H 41 BrO 3 , the Br atom bonded to C 3 is β-axially oriented and is (-)-synclinal to the C4-C5 bond. The six-membered rings (A, B and C) have chair conformations as expected. The five-membered ring (D) adopts a distorted 13β-envelope conformation. The A/B ring junction is cis and the B/C and C/D ring junctions are both trans.

Methyl 4β-bromo-7α-cathyloxy-3-oxo-5β-cholanoate

In the title compound, methyl 4β-bromo-7α-ethoxy-carbonyloxy-3-oxo-5β-cholanoate, C 28 H 43 BrO 6 , the Br-C4 bond is oriented equatorially and (-)-antiperiplanar with respect to the C5-C10 bond. The six-membered rings (A, B and C) have the usual chair conformations, while the five-membered ring (D) adopts a distorted 13β,14α-half-chair conformation. The A/B ring junction is cis, and the B/C and C/D ring junctions are both trans.