A new regio- and diastereoselective 1,3-dipolar cycloaddition reaction of 7,9-bis[(E)-arylidene]-1,4-dioxa-spiro[4,5]decane-8-ones,
sarcosine/1,3-thiazolane-4-carboxylic acid and acenapthequinone has been developed for the synthesis of
trispiropyrrolidine/thiapyrrolizidine derivatives using 2,2,2-trifluoroethanol as a green solvent. The solvent (TFE) can be readily separated
from reaction products and recovered in excellent purity for direct reuse. A regio- and stereochemical outcome of the cycloaddition reaction
was ascertained by X-ray crystallographic study.
Key words: Spiroheterocycles; cycloaddition; azomethine ylides; 2,2,2-trifluoroethanol; trispiropyrrolidine and thiapyrrolizidine
derivatives
|