Sulfur ylides. 12. Optically active keto stabilized sulfur ylide obtained from L-proline: synthesis and study

Optically active keto stabilized sulfur ylide was synthesized from L-proline. The reactions of the ylide with methyl acrylate and methyl vinyl ketone afforded 1,2-disubstituted cyclopropanes. In the case of acrylonitrile, a mixture of 1,2- and 1,1-disubstituted cyclopropanes was obtained. Acylation of the ylide with acetic anhydride gave twice stabilized sulfur ylide.     

Sulfur ylides. 10. Modified method for the synthesis of pyrrolizine- and indolizinediones

A modified method for the synthesis of derivatives of pyrrolizinedione and indolizinedione was proposed. The method is based on the intramolecular cyclization of keto-stabilized sulfur ylides generated in situ from diazo ketones and Me₂S in the presence of Rh₂(OAc)₄.