596105-03-2Relevant academic research and scientific papers
Ring expansion of 2-(α-hydroxyalkyl)azetidines: A synthetic route to functionalized pyrrolidines
Durrat, Francois,Sanchez, Monica Vargas,Couty, Francois,Evano, Gwilherm,Marrot, Jerome
experimental part, p. 3286 - 3297 (2009/04/07)
A series of 2-(α-hydroxyalkyl)azetidines synthesized from enantiomerically pure β-amino alcohols and presenting various patterns both on the four-membered ring and on the adjacent hydroxy group were treated with either thionyl chloride or methanesulfonyl chloride in the presence of triethylamine. The thus-prepared 2-(α-chloro- or α- methanesulfonyloxyalkyl) azetidines were shown to rearrange stereospecifically into 3-(chloro- or methanesulfonyloxy)pyrrolidines. When this rearrangement is conducted in the presence of an added nucleophile (NaN3, KCN, KOH, or NaOAc), the produced pyrrolidine incorporates the added nucleophile at C-3 stereospecifically. The relative configuration of the substituents in the formed pyrrolidines is consistent with a mechanism involving the formation of an intermediate bicyclic aziridinium ion, which is opened regioselectively at the bridgehead carbon atom. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Highly stereoselective ring expansion of enantiopure α-hydroxyalkyl azetidines
Couty, Fran?ois,Durrat, Fran?ois,Prim, Damien
, p. 5209 - 5212 (2007/10/03)
Stereodefined α-hydroxyalkyl azetidines, prepared in a few steps from enantiopure β-amino alcohols, are chlorinated or transformed into methanesulfonyloxymethyl derivatives in good yields. Heating of these compounds in chloroform or dimethylformamide induces a stereospecific ring enlargement to give 3-chloro or 3-methanesulfonyloxy pyrrolidines. The ease of this rearrangement depends on the nature of the migrating group (Cl- or MsO-), of the class of the starting alcohol (primary or secondary) and of the relative stereochemistry of the starting material.
