84019-04-5Relevant academic research and scientific papers
Aprotic Conjugate Addition of Allyllithium Reagents Bearing Polar Groups to Cyclic Enones. 1. 3-Alkylallyl Systems
Binns, Malcolm R.,Haynes, Richard K.,Katsifis, Andrew G.,Schober, Paul A.,Vonwiller, Simone C.
, p. 5411 - 5423 (2007/10/02)
The conjugate addition of lithiated (E)- and (Z)-oct-2-enyl sulfoxides and phosphine oxides, but-2-enyl sulfoxides, phosphine oxides and phosphonates, and 3,3-dimethylallyl and allyl sulfoxides to cyclic enones has been examined.The E and Z carbanions react in highly diastereoselective fashion with five-membered cyclic enones to deliver respectively syn and anti vinylic sulfoxides, phosphine oxides, and phosphonates.Hexamethylphosphoric triamide has no regiochemical influence on these reactions.The regiochemical and stereochemical outcomes of these reactions are rationalized in terms of planar lithiated reagents in which Li+ is bound to oxygen attached to sulfur or phosphorus of the polar group and a 10-membered "trans-decalyl"- or "trans-fused chair-chair"-like transition-state model in which the lithiated reagent adopts an endo orientation over one face of the enone such that for the reagent, the 3-alkyl group is pseudoequatorial, and for the Z, pseudoaxial.
Synthesis of Substituted Indans as Prostacyclin Analogues
Phialas, Memnon,Sammes, Peter G.,Kennewell, Peter D.,Westwood, Robert
, p. 687 - 695 (2007/10/02)
A route is described to the substituted indans (8) and (10), prepared as analogues of prostaglandin I2 (prostacyclin).Two key steps in the synthesis involve the regiospecific attack of lithium salts from allylic sulphides onto indene oxides and, after oxidation to the corresponding sulphoxides, their reductive rearrangement to the required diols.Using model indene oxides, attempts have been made to direct the stereochemistry of the exocyclic hydroxy group by steric control during formation of the precursor sulphide.
