601-55-8

Upstream product

• 108-75-8 2,4,6-trimethyl-pyridine 
• 1452-34-2 2α-bromo-5α-cholestan-3-one 
• 17697-12-0 benzeneseleninic anhydride 
• 1900-72-7 C₂₉H₅₀OS 
• 566-88-1 dihydrocholesterone 
• 2516-50-9 2α-chloro-5α-cholestan-3-one 
• 68-12-2 N,N-dimethyl-formamide 
• 41602-10-2 2-bromocholestan-3-one 

Downstream Products

• 571-40-4 5α-androst-1-ene-3,17-dione 
• 116027-95-3 5α-cholesten-(1)-one-(3)-semicarbazone 
• 162460-20-0 1α-(dimethylphenylsilyl)-5α-cholestan-3-one 
• 566-88-1 (5α)-cholestan-3-one 
• 5793-57-7 5α-cholest-1-en-3β-yl benzoate 
• 76043-43-1 C₃₄H₅₁NO₃S 
• 7485-18-9 4-aza-A-homo-5α-cholest-1-en-3-one 
• 191481-88-6 C₅₄H₇₀O₆S 
• 1923-42-8 5α-cholest-1-en-3-one-(2,4-dinitro-phenylhydrazone) 
• 566-44-9 cholestane-1-one 

Relevant academic research and scientific papers

Functionalisation of Saturated Hydrocarbons. Part 13. Futher Studies on the Gif Oxidation of Cholestane Derivatives

The oxidation of cholest-4-en-3-one by the GifIV system to give progesterone has been studied over the temperature range -40 to +80 deg C.The optimum temperature is ca. +20 deg C.Below 0 deg C the yield of progesterone diminishes and the formation of a new compound, 25-hydroxycholest-4-en-3-one, is observed.The latter has been synthesised from lithocholic acid.An unexpected major product of the oxidation was A-nor-5β-cholestan-3-one, identified by comparison with an authentic sample.

A SYNTHESIS OF 11-HOMO-ALDOSTERONE

A synthesis of 11-homo-aldosterone acetate (1a) is described. 3β-Acetoxy-11-methylene-5α,25D-spirostan (3) was converted in 4 steps into 3β-acetoxy-11β-acetoxymethyl-5α-pregnan-20-one (9, Chart I), which was photocyclized to 20a, saponified regioselectively, and oxidized to 3-oxo-11β-acetoxymethyl-18,20-cyclopregnan-20α-ol-3-one (22, Chart II).Introduction of the 1,4-diene in 22 followed by a selective reduction of the 1-ene afforded 11β-acetoxymethyl-18,20-cyclopregn-4-en-20α-ol-3-one (26).Finally, the 18,20-cyclo ring of 26 was manipulated through 30, 31, 32, 33 to produce 1a.The bulky 11β-acetoxymethyl group distorted the steroid molecule to such an extent that the routine photochemical functionalization of the angular Me-18 via a nitrite or a hypoiodite became inoperative and routine procedures for introduction of a 4-ene into 5α-3-one via a 1,4-dien-3-one were unsuccessful.Two new methods for the introduction of a 4-ene into steroidal 5α-3-ones were investigated using 5α-cholestanone and 5α-dihydrotestosterone as models.The first route, which was applicable to the synthesis of 1a, was the stepwise introduction of a 1-ene and a 4-ene utilizing Sharpless's acidic phenylselenyl chloride procedure, followed by a selective reduction of the 1-ene.The second route, which appeared equally promising, was protection of the C-2 site with N-methylanilinomethylene followed by introduction of the 4-ene and subsequent deprotection of the C-2.

Removal of Thioacetal Protecting Groups by Benzeneseleninic Anhydride

A number of thioacetals were deprotected with benzeneseleninic anhydride in good yield.The reaction worked particularly well for hindered spiro-1,3-dithiolans of 2,2,6-trimethylcyclohexanone and fenchone, and in examples where other literature methods had failed.