120950-90-5Relevant academic research and scientific papers
Regioselective spiroannulations of α-acetyl lactones
Christoffers, Jens,Oertling, Heiko,Frey, Wolfgang
, p. 1665 - 1671 (2003)
Monocyclic spiroannulation precursors 3a-c were obtained by Michael reactions of a-acetyl lactones 6a-c with methyl vinyl ketone (7), The selective formation of either regioisomer of both β-oxo (5a-c) and δ-oxo (4a-c) lactones from 3a-c was achieved by varying the reaction conditions. The δ-oxo lactones 4a-c were obtained under basic (buffered) conditions in a pyrrolidine/AcOH system. Under acidic conditions, the annulation reaction afforded β-oxo lactones 5a-c. Byproducts 8b,c were identified to be the decomposition products of β-oxo lactones 5b and 5c by comparison with the spectra of the alcohols 10b,c derived directly from δ-oxo lactones 4b and 4c by saponification/decarboxylation. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
STEREOSELECTIVE CYCLIZATION OF ALLYLSILANES AND -STANNANES
Schinzer, Dieter,Allagiannis, Christos,Wichmann, Sabine
, p. 3851 - 3868 (2007/10/02)
The syntheses and additions of allylsilanes, and -stannanes to enones and dienones forming spiro- and fused-bicyclic products are described.The stereoselectivity observed is dependent on the Lewis acid used.The tin terminator reverses the stereoselectivit
