241473-86-9Relevant academic research and scientific papers
Samarium(ii)-mediated 4-exo-trig cyclisations of unsaturated aldehydes. a stereoselective approach to functionalised cyclobutanols
Johnston, Dcrek,McCusker, Catherine F.,Muir, Kenneth,Procter, David J.
, p. 681 - 695 (2007/10/03)
γ,δ-Unsaturated aldehydes having a fully substituted centre in either the α- or β-positions, have been prepared from substituted γ-butyrolactones and undergo efficient 4-exo-trig cyclisation on treatment with sarnarium(ii) iodide to give functionalised cyclobutanols. In all cases cyclisation occurs with complete diastereocontrol to give anti-cydobutanol products. The stereochemistry of the products has been confirmed by NOE and X-ray crystallographic studies. In the cyclisation of substrates having a third substituent on the double bond, α- to the ester, significant control is achieved at the third newly formed stereocentre lying outside the ring. The origin of the stereoselectivity at this third centre and its marked dependence on cosolvent are discussed. The Royal Society of Chemistry 2000.
Samarium(II)-mediated 4-exo trig ketyl-olefin cyclisation of unsaturated aldehydes. A general, stereoselective synthesis of functionalised cyclobutanols
Johnston, Derek,McCusker, Catherine M.,Procter, David J.
, p. 4913 - 4916 (2007/10/03)
γ,δ-Unsaturated aldehydes having a quaternary centre in either the α or β-position, have been prepared from substituted γ-butyrolactones and undergo efficient 4-exo-trig ketyl-olefin cyclisation on treatment with samarium(II) iodide to give functionalised cyclobutanols. In all cases cyclisation occurs with complete diastereocontrol to give anti-cyclobutanol products. In the cyclisation of substrate 4ab, significant stereochemical control is achieved at three contiguous chiral centres. Both unsaturated esters and vinyl sulfones have been employed as substrates in the reaction.
