Stereoselective de novo synthesis of (5R)-3,4:5,6-di-O-isopropylidene-d-ribo-hexos-5-ulo-5,2-furanose
摘要:
A concise and stereoselective de novo synthesis of the protected oxidized sugar (5R)-3,4:5,6-di-O-iso-propylidene-D-ribo-hexos-5-ulo-5,2-furanose is described. The synthetic sequence involves a stereoselective proline-catalyzed aldol reaction of an orthogonally protected L-glyceraldehyde derivative and 2,2-dimethyl-1,3-dioxan-5-one, to obtain 5-0-acetyl-6-0-benzy1-1,3-isopropylidene-L-psicose as a key intermediate, and the final product in 5 steps and 38% yield. (C) 2016 Elsevier Ltd. All rights reserved.
Concise synthesis of orthogonally diprotected l-glyceraldehyde
摘要:
Orthogonally diprotected L-glyceraldehyde was efficiently prepared from readily available starting materials, allowing to obtain a highly stable and synthetically versatile chiral building block compared to known symmetrically protected derivatives. (C) 2013 Elsevier Ltd. All rights reserved.
Stereoselective preparations of protected rare sugars and derivatives, namely l-psicose, l-altritol, and l-talose have been achieved in 70, 44, and 18% yield, respectively, from an orthogonallyprotected l-glyceraldehyde derivative. The key step is the stereoselective proline-catalyzed aldol reaction of this aldehyde with dioxanone. Stereoselective preparations of protected rare sugars and derivatives