Stereoselective synthesis of carbohydrate-derived N-Sulfonyl aziridines

A novel reaction of iodomethyllithium with a variety of sugar-derived N-sulfinyl imines, under very mild conditions, is described. N-Sulfonyl aziridines were easily obtained in high yields and in moderate to good stereoselectivities through an addition/oxidation protocol. A mechanism is proposed that is supported by the results of X-ray diffraction studies. © Georg Thieme Verlag Stuttgart · New York.We appreciate financial support from the Spanish Ministerio de Economía y Competitividad (CTQ2010-14959, MAT2006-01997, MAT2010-15094 and Factoría de Cristalización Consolider Ingenio 2010), Fundação para a Ciência e a Tecnologia (project PEst-C/QUI/UI0062/2011) and FEDER funding. C.C.F. and N.A. thank MICINN for a Juan de la Cierva contract and FICYT for a ­predoctoral fellowship, respectively. R.S. thanks the FCT for an ­‘Investigador Auxiliar’ position.Peer Reviewe

Б1.В.ДВ.11.02 Точность технологических машин

The highly diastereoselective samarium diiodide and D(2)O-promoted conjugate reduction of homochiral (E)- and (Z)-benzylidene and isobutylidene diketopiperazines (E)-5,7 and (Z)-6,8 has been demonstrated. This methodology allows the asymmetric synthesis of methyl (2S,3R)-dideuteriophenylalanine 27 in > or = 95% de and >98% ee, and (2S,3R)- or (2S,3S)-dideuterioleucine-(S)-phenylalanine dipeptides 37 and 38 in moderate de, 66% and 74% respectively. A mechanism is proposed to account for this process