TY - JOUR
T1 - Synthesis of Zymosterol, Fecosterol, and Related Biosynthetic Sterol Intermediates
AU - Dolle, Roland E.
AU - Kruse, Lawrence I.
AU - Schmidt, Stanley J.
AU - Erhard, Karl F.
PY - 1989/1
Y1 - 1989/1
N2 - 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 Δ24(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 Δ8, 24(28)-sterols with high regiocontrol.
AB - 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 Δ24(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 Δ8, 24(28)-sterols with high regiocontrol.
UR - http://www.scopus.com/inward/record.url?scp=0024557573&partnerID=8YFLogxK
U2 - 10.1021/ja00183a042
DO - 10.1021/ja00183a042
M3 - Article
AN - SCOPUS:0024557573
SN - 0002-7863
VL - 111
SP - 278
EP - 284
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 1
ER -