104528-39-4

Upstream product

• 57-83-0 Progesterone 

Downstream Products

• 60966-95-2 4-pregnene-3α,20β-diol 
• 15780-16-2 4-pregnene-3α,20S-diol 
• 25680-68-6 3α-hydroxy-4-pregnen-20-one 
• 57-83-0 Progesterone 

Relevant academic research and scientific papers

Synthesis of the allylic gonadal steroids, 3α-hydroxy-4-pregnen-20-one and 3α-hydroxy-4-androsten-17-one, and of 3α-hydroxy-5α-pregnan-20-one

A method for the convenient synthesis of the recently isolated allylic gonadal steroids, 3α-hydroxy-4-pregnen-20-one (3α-dihydroprogesterone; 3α-DHP) and 3α-hydroxy-4-androsten-17-one (3α-HA), was developed using 4-pregnene-3,20-dione (progesterone) and 4-androstene-3,17-dione as substrates and potassium trisiamylborohydride (KS-Selectride) as reducing agent. Similar reactions were also used for the reduction of 5α-pregnane-3,20-dione to 3α-hydroxy-5α-pregnan-20-one (3α-HP). The yields were about 15%, 50%, and >90% for 3α-DHP, 3α-HA and 3α-HP, respectively. Structures of the products, including the 3β-isomers and the 17α-epimer, formed in these reactions were determined by NMR and mass spectroscopic methods.

SELECTIVITE DE LA REDUCTION DE L'ANDROSTEN-4 DIONE-3,17 ET DE LA PROGESTERONE PAR DIVERS BOROHYDRURES: ROLE DE L'ASSISTANCE ELECTROPHILE PAR LE CATION OU UN SOLVANT HYDROXYLE

The reduction of Δ4-androsten-3,17 dione 1 and of progesterone 2 by nBu4NBH4 is highly chemisoselective: in THF only the α-enone moiety is reduced, the saturated C17 or C20 keto group being kept unchanged.When TMEDA is added, saturated alcohols are obtained, without any allylic alcohol when the reaction goes to completion.However this reduction is poorly stereoselective as 70:30 mixtures of A/B cis and trans ring junction compounds are obtained.In MeOH, the saturated keto group is more than 90percent selectively reduced.However, the reduction of 1 and 2 by LiBH4 and Zn(BH4)2 is poorly chemioselective.These results are interpreted in terms of competition between electrophilic assistance and steric effects.

Preparation of a Polymer-supported Diol and Its Use in isolating Aldehydes and Ketones from Mixtures and as a Protecting Group for Aldehydes and Ketones

Reaction of cross-linked chloromethylated polystyrenes with 3-mercaptopropane-1,2-diol and sodium hydroxide under phase-transfer conditions gave polymers containing diol residues.A range of aldehydes and ketones were successfully bound to these polymers via acetal formation.The aldehydes and ketones were released by treating the products with aqueous dioxane in the presence of toluene-p-sulphonic acid.The polymer-supported diol could be used to isolate aldehydes or ketones from mixtures with other compounds and to separate a 3-oxosteroid from a 17- or a 20- oxosteroid.The supported diol was successfully used to protect the aldehyde group of undec-10-enal whilst the terminal vinyl group was transformed into -CH2CH2OCOPh.Attempts to monoprotect dicarbonyl compounds were unsuccessful.

METAL-ASSISTED REACTIONS-12. UNUSUAL SELECTIVITY IN THE REDUCTION OF KETONES WITH ZINC OR CADMIUM BIS-TETRAHYDROBORATE/DIMETHYLFORMAMIDE COMPLEX

Zinc bis-tetrahydroborate forms a solid complex with dimethylformamide (DMF) of composition, Zn(BH4)2*1.5DMF.Unlike zinc bis-tetrahydroborate itself, the complex with DMF can be stored as a solid at room temperature.Ketones and aldehydes are reduced to the corresponding alcohols by the complex but the mechanism of reduction appears to be different from that using zinc bis-tetrahydroborate itself and from other tetrahydroborates in that only one hydride equivalent from each BH4- unit is utilized and not four.Further, although saturated aliphatic ketones are reduced rapidly to alcohols, aromatic ketones react much more slowly and α,β-unsaturated ketones react very slowly so that the complex appears to have selective reducing potential with regard to different classes of ketones.It is also apparent that the zinc bis-tetrahydroborate/DMF complex reduces sterically hindered saturated ketones much more slowly than it does unhindered ketones.An analogous cadmium bis-tetrahydroborate/DMF complex can be prepared in solution and reacts with ketones similarly to the zinc complex.