139437-47-1Relevant articles and documents
Chemoselective and stereoselective synthesis of gem-difluoro-β-aminoesters or gem-difluoro-β-lactams from ethylbromodifluoroacetate and imines during Reformatsky reaction
Boyer, Nicolas,Gloanec, Philippe,De Nanteuil, Guillaume,Jubault, Philippe,Quirion, Jean-Charles
, p. 12352 - 12366 (2008/03/12)
The chemoselective and stereoselective synthesis of gem-difluoro-β-aminoesters or gem-difluoro-β-lactams was investigated from ethylbromodifluoroacetate and imines during Reformatsky reaction. Influence of various reaction parameters, such as nature of the amine part, nature of the chiral auxiliary, was evaluated. High levels of stereoselectivity (up to 98%) were obtained for gem-difluoro-β-aminoesters and gem-difluoro-β-lactams using either (R)-phenylglycinol or (R)-methoxyphenylglycinol.
Studies towards the total synthesis of solanoeclepin A: Synthesis of the 7-oxabicyclo[2.2.1]heptane moiety and attempted seven-membered ring formation
Benningshof, Jorg C. J.,Blaauw, Richard H.,Van Ginkel, Angeline E.,Van Maarseveen, Jan H.,Rutjes, Floris P. J. T.,Hiemstra, Henk
, p. 1693 - 1700 (2007/10/03)
This paper details studies towards the total synthesis of solanoeclepin A (1), the most active natural hatching agent of potato cyst nematodes. The first goal was the preparation of the tetracyclic left-handed substructure 2 in enantiopure form. The 7-oxabicyclo[2.2.1]heptane moiety was obtained via a diastereoselective intramolecular Diels-Alder strategy by using (R)-phenylglycinol as a chiral auxiliary as pioneered by Mukaiyama. A chromium-mediated nickel-catalysed coupling of aldehyde 5 with vinyl triflate 6 gave α,β-unsaturated lactone 18 as a single stereoisomer. The seven-membered ring was expected to arise from a McMurry coupling of dialdehyde 4. Surprisingly, oxidation of diol 24 did not lead to the desired dialdehyde 4, but to the eight-membered ring lactone 25.
Diastereoselective addition of silyl enol ether to chiral imines and 1,3-oxazolidines using a Lewis acid
Higashiyama, Kimio,Kyo, Hideyoshi,Takahashi, Hiroshi
, p. 489 - 490 (2007/10/03)
The Lewis acid promoted reaction of silyl enol ether to chiral imines and 1,3-oxazolidines derived from (R)-phenylglycinol afforded with good diastereoselectivity the (R,R)-β-amino ester derivatives from the imines, and the (R,S)-β-amino ester derivatives from the 1,3-oxazolidines.