Synthesis of Mono-O-tritylraffinoses and Deca-O-acetylraffinoses

Abstract
Starting from raffinose (1), its 6″-O-trityl (2) and 6′-O-trityl derivative (6) have been prepared. Acetylation of 2 and 6 gave deca-O-acetyl-6″-O-tritylraffinose (3) and deca-O-acetyl-6′-O-tritylraffinose (7) respectively. Detritylation of 3 gave two products: 1′,2,2″,3,3′,3″,4,4′,4″,6′-deca-O-acetylraffinose (4) as a main product and 1′,2,2″,3,3′,3″,4,4′,6′,6″-deca-O-acetylraffinose (5) as a minor product, which were successfully separated by a column chromatography. On the other hand, detritylation of 7 gave 1′,2,2″,3,3′,3″,4,4′,4″,6″-deca-O-acetylraffinose (8) as a sole product. Their structures were established by NMR spectra, together with a chemical evidence.