L-Proline is utilized as an efficient organocatalyst for the synthesis of substituted flavanones and chalcones in good yields. The efficiency of the catalyst was proved with a variety of substrates ranging from electron-deficient to electron-rich aryl aldehydes and 2-hydroxyacetophenones. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis of New Substituted 4,5-Dihydro-3H-spiro[1,5]-benzoxazepine-2,4′-piperidine and Biological Properties
The reduction of substituted spiro-piperidinyl chromanone oximes with DIBAH reagents has been known to afford the corresponding substituted 4,5-dihydro-3H-spiro[1,5]-benzoxazepine-2,4′-piperidine. The position and electronic effects of the substituents on the aryl moiety control the observed rearrangement. Spiro-benzoxazepine analogue 5j represents a key intermediate for the creation of a library of