Asymmetric synthesis. 29. Preparation of 1,8-diazaspiro[5.5]undecane derivatives
From 2-cyano-6-phenyloxazolopiperidine, two highly efficient routes have been developed for the asym. synthesis of the spiropiperidine system: 1,8-diazaspiro[5.5]undecane. The key step was generation of the imine salts from the functionalized alpha -amino nitrile I, by nucleophilic addn. of a suitable organometallic reagent to the nitrile group followed by, in situ, intramol. nucleophilic alkylation. A reductive-cyclization procedure allowed the prepn. of nonsubstituted and monosubstituted spiro compds. II (R = H, pentyl), while an alkylation-cyclization procedure led to the disubstituted spiro deriv. III, an aza analog of perphydrohistrionicotoxin. [on SciFinder (R)]
1993
58
23
6451
6
CAN 120:77507
31-5
Alkaloids
Fac. Sci. Pharm.,Univ. Rene Descartes,Paris,Fr.
Journal
written in English.
151746-68-8P; 151746-71-3P; 151746-76-8P; 151850-99-6P Role: SPN (Synthetic preparation), PREP (Preparation) (asym. synthesis of); 151746-69-9P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and Grignard reaction of, with pentylmagnesium bromide); 151746-66-6P; 151746-70-2P; 151746-73-5P; 151746-75-7P; 151850-98-5P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and hydrogenolysis of); 151746-72-4P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and reaction of, with cyanide); 151746-67-7P; 151746-74-6P; 151746-77-9P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 151746-65-5P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn., redn., and intramol. cyclization of); 88056-92-2 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with chloroiodopropane); 6940-76-7 (1-Chloro-3-iodopropane) Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with oxazolopyridine deriv.)
REVIEWED
OTHER