277757-89-8Relevant academic research and scientific papers
Ring expansion versus cyclization in 4-oxoazetidine-2-carbaldehydes catalyzed by molecular iodine: Experimental and theoretical study in concert
Alcaide, Benito,Almendros, Pedro,Cabrero, Gema,Callejo, Ricardo,Pilar Ruiz,Arno, Manuel,Domingo, Luis R.
supporting information; experimental part, p. 1688 - 1700 (2010/09/09)
Molecular iodine (10 mol%) efficiently catalyzes the ring expansion of 4-oxoazetidine-2-carbaldehydes in the presence of tert-butyldimethylsilyl cyanide, or allylic and propargylic trimethylsilanes to afford protected 5-functionalized-3,4-dihydroxypyrrolidin-2-ones with good yield and high diastereoselectivity, through a C3-C4 bond cleavage of the β-lactam nucleus. Interestingly, in contrast to the iodine-catalyzed reactions of 3-alkoxy-β-lactam aldehydes which lead to the corresponding γ-lactam derivatives (rearrangement adducts), the reactions of 3 aryloxy-β-lactam aldehydes under similar conditions gave β-lactam-fused chromanes (cyclization adducts) as the sole products, through exclusive electrophilic aromatic substitution involving the C3 aromatic ring and the carbaldehyde. In order to support the mechanistic proposals, theoretical studies have been performed.
An efficient synthesis of highly functionalised 4-substituted 2-azetidinones by a stereoselective intermolecular Diels-Alder reaction of different types of 2-azetidinone-tethered dienes
Alcaide, Benito,Almendros, Pedro,Salgado, Nati R.,Martinez-Alcazar, Mari Paz,Hernandez-Cano, Felix
, p. 2001 - 2009 (2007/10/03)
The diastereoselectivity of the intermolecular Diels-Alder reaction of 2-azetidinone-tethered dienes was investigated. Diene precursors were prepared from 4-azetidinone-2-carbaldehydes through an allylation-dehydration process or by the sequence Wittig re
Stereoselective allylation of 4-oxoazetidine-2-carbaldehydes. Application to the stereocontrolled synthesis of fused tricyclic β-lactams via intramolecular Diels-Alder reaction of 2-azetidinone-tethered trienes
Alcaide, Benito,Almendros, Pedro,Salgado, Nati R.
, p. 3310 - 3321 (2007/10/03)
Allylation reactions of racemic and optically pure 4-oxoazetidine-2- carbaldehydes were investigated both under anhydrous conditions and in aqueous media. Different Lewis acid or metal mediators showed varied diastereoselectivities on product formation du
