7408-47-1

Upstream product

• 117439-18-6 Benzoic acid (3S,5R,10S,13R,14R,17R)-17-((R)-4-hydroxy-1,5-dimethyl-hexyl)-4,4,10,13-tetramethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117439-06-2 Benzoic acid (3S,5R,10S,13R,17R)-17-[(R)-1,5-dimethyl-4-(2,2,2-trifluoro-acetoxy)-hexyl]-4,4,10,13-tetramethyl-15-trifluoromethanesulfonyloxy-2,3,4,5,6,7,10,11,12,13,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117438-85-4 (3β,5α,24R,S)-4,4-Dimethylcholesta-8,14-diene-3,24-diol 3-benzoate 24-trifluoroacetate 
• 117438-89-8 (3β,5α,24R,S)-3-(Benzoyloxy)-4,4-dimethyl-24-(trifluoroacetoxy)cholest-8(14)-en-15-one 
• 117439-09-5 Benzoic acid (3S,5R,10S,13R,17R)-17-[(R)-4-(tert-butyl-dimethyl-silanyloxy)-1,5-dimethyl-hexyl]-4,4,10,13-tetramethyl-2,3,4,5,6,7,10,11,12,13,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117439-16-4 Benzoic acid (3S,5R,10S,13R,14R,17R)-17-[(R)-4-(tert-butyl-dimethyl-silanyloxy)-1,5-dimethyl-hexyl]-4,4,10,13-tetramethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117439-14-2 Benzoic acid (3S,5R,10S,13R,14R,15S,17R)-17-[(R)-4-(tert-butyl-dimethyl-silanyloxy)-1,5-dimethyl-hexyl]-15-hydroxy-4,4,10,13-tetramethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 209850-48-6 Benzoic acid (3S,5R,9R,10R,13R,17R)-17-((S)-2-hydroxy-1,5-dimethyl-4-oxo-hexyl)-4,4,10,13-tetramethyl-15-oxo-2,3,4,5,6,7,9,10,11,12,13,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117438-96-7 Benzoic acid (3S,5R,9R,10R,13R,17R)-17-((E)-(R)-1,5-dimethyl-4-oxo-hex-2-enyl)-4,4,10,13-tetramethyl-15-oxo-2,3,4,5,6,7,9,10,11,12,13,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester 
• 117438-97-8 3β-(Benzoyloxy)-4,4-dimethyl-5α-cholest-8(14)-ene-15,24-dione 
• 103751-19-5 (3β,5α,22E)-3-(benzoyloxy)-4,4-dimethylergosta-8(14),22-dien-15-one 
• 209850-50-0 3β-(Benzoyloxy)-24-hydroxy-4,4-dimethyl-5α-cholest-8(14)-ene-15-one 
• 117438-93-4 (3β,5α,20S)-3-(Benzoyloxy)-4,4-dimethyl-15-oxopregn-8,14-ene-20-carboxaldehyde 
• 563-80-4 3-methyl-butan-2-one 

Downstream Products

• 7448-02-4 4,4-dimethyl-5α-cholesta-8,24-dien-3β-ol 

Relevant academic research and scientific papers

Synthesis of zymosterol, fecosterol, and related biosynthetic sterol intermediates

The first syntheses of sterol biosynthetic intermediates zymosterol(4), 4,4-dimethylzymosterol(5), cholesta-8,14,24-trien-3β-ol(6), the 4,4-dimethyl analogue 7, and fecosterol (8) are described in detail. Multigram quantities of key intermediates 16 and 17 were efficiently prepared from known enones 20 and 21 (eight steps, 35% overall yield). Novel entry into Δ8-sterols was achieved through regiospecific hydroboration/deoxygenation of the 8,14-diene systems. Sterols containing Δ24- or Δ(24(28))-olefins were obtained from C24-hydroxy intermediates either via dehydration using bis[α,α-bis(trifluoromethyl)benzenemethanolato]diphenylsulfur in CH2Cl2 or via Swern oxidation/Wittig olefination, respectively. In this way, 16 and 17 were converted to the desired Δ8,24-, Δ8,14,24-, and Δ(8,24(28))-sterols with high regiocontrol.