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Deacetoxylation

Several reports have indicated that 17-acetoxy-20-ketopregnane derivatives are deacetoxylated readily by both calcium and lithium. The diacetate of 17a-pregna-l,3,5(10)-triene-3,17j5-diol-20-one (79) is reduced to pregna-l,3,5(10)-trien-3-ol-20-one (80) in 76% yield with calcium in ammonia, and... [Pg.45]

From the data available, calcium appears to be generally useful for the deacetoxylation of ketol acetates, whereas the utility of lithium is definitely established only for 17-acetoxy-20-ketopregnane derivatives. [Pg.46]

Lithium reductive deacetoxylation of the tetrahydropyranyl ether of 17o -ace-toxypregn-5-en-3/3-ol-20-one, 56... [Pg.496]

Reduction with sodium borohydride without protecting groups, 92 Reductive deacetoxylation of ll-keto-12/3-hydroxytigogenin diacetate, 53 Reductive methylation of the 3-ethylene ketal of pregna-5, 16-diene-3, 20-dione, 54... [Pg.497]

A general mechanism for either deacetoxylation reaction can be pictured as follows... [Pg.171]

Deacetoxylation of 128e gave erythrocarine [Eq. (6.101)]. Using a similar procedure, Hatakeyama succeeded in the total synthesis of erythravine ... [Pg.191]

Reaction 5c can also be separately demonstrated to take place under homologation conditions (CO/H2 = 1, T = 155 °C) with RU/CH3I (or Znl2) or Rh/Ru/CH3l (or Znl2) catalysts. However, the use of neat EDA as feed results in a low selectivity to ethyl acetate. Instead, a rapid pol5mierization-deacetoxylation takes place ... [Pg.161]

Reductive deacetoxylation.1 This naphthalenide in HMPT is recommended for reductive cleavage of a-aceloxy esters.2 Lithium in liquid ammonia can be used, but... [Pg.362]

Lithium borohydride, 62 Lithium f-butoxide, 69 Lithium cyanohydridoborate, 92 Lithium diisopropylamide, 477 Lithium reductive deacetoxylation, 56 Lithium reduction of 17a-ethynyl-19-nortestosterone, 55... [Pg.262]

See other pages where Deacetoxylation is mentioned: [Pg.391]    [Pg.391]    [Pg.1]    [Pg.38]    [Pg.46]    [Pg.53]    [Pg.170]    [Pg.172]    [Pg.173]    [Pg.452]    [Pg.452]    [Pg.456]    [Pg.464]    [Pg.442]    [Pg.445]    [Pg.52]    [Pg.483]    [Pg.467]    [Pg.28]    [Pg.32]    [Pg.272]    [Pg.298]    [Pg.93]    [Pg.94]    [Pg.234]    [Pg.234]    [Pg.236]    [Pg.334]    [Pg.136]   
See also in sourсe #XX -- [ Pg.506 ]

See also in sourсe #XX -- [ Pg.23 , Pg.414 ]

See also in sourсe #XX -- [ Pg.23 , Pg.414 ]



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Lithium reductive deacetoxylation

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