Facile and selective metalation of 7-dehydrocholesterol (pro-vitamin D3)
Successive treatment of 7-dehydrocholesterol (I) with Me3SiCH2K in THF, dry ice, mineral acid, and diazomethane gives a regioisomerically pure, homoconjugated ester II as a diastereomeric mixt., the minor component of which is thermodynamically more stable than the conjugated isomer III. [on SciFinder (R)]
Keywords: Steroids Role: RCT (Reactant) ; RACT (Reactant or reagent) (metalation of dehydrocholesterol by trimethylsilylmethylpotassium ; regiochem. of); Regiochemistry (of metalation ; of dehydrocholesterol by trimethylsilylmethylpotassium); Metalation (regioselect ; dehydrocholesterol metalation carboxylation regiochem; provitamin D3 metalation silylmethylpotassium; cholestadienecarboxylate hydroxy
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
written in English.
91667-58-2 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation-carboxylation of, regiochem. of); 91667-60-6P; 91667-61-7P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and base-catalyzed isomerization of); 91667-59-3P; 91740-66-8P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and esterification of); 91667-62-8P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of)
Record created on 2006-03-03, modified on 2016-08-08