A new procedure for the preparation of beta-keto-delta-lactones from sugars and their transformation into glycosyl acceptors in disaccharides synthesis
[reaction: see text] Glycals are effective starting materials for the synthesis of enantiopure beta-ketone-delta-lactones. They are easily transformed, through a two-step, one-pot reaction, into the corresponding alpha,alpha'-dioxothiones which in turn can be quantitatively trapped with dienophiles in inverse electron-demand [4 + 2] cycloadditions. The reaction of dioxothione 8b with endo and exo glucals allowed the elaboration of a new protocol to prepare 2-thio- or 2-deoxydisaccharides stereoselectively.
Bartolozzi
A
Centro CNR Chimica dei Composti Eterociclici, Dipartimento di Chimica Organica, Universita di Firenze, Italy.
Capozzi
G
Menichetti
S
Nativi
C