Tin-Free radical reactions of carbohydrate derivatives using allylsulfone derivatives as precursors

Abstract

We have studied tin-free radical reactions of carbohydrate derivatives. To perform the tin-free radical reaction, we synthesized allyl sulfonyl C-glycoside from ribose and glucose and C-branched glycoside from glucose derivatives. Radical reactions of allylsulfonyl C-glycoside of ribose affored the desired cyanation, allylation, vinylation and acylation products in good yields. In the case of allyl sulfonyl C-glycoside of glucose, the yields were lower and reaction times were longer than allylsulfonyl C-glycoside of ribose. In the case of C-branched glycoside, C(3) branched glycoside gave desired products but C(2), C(6) branched glycoside did not. In case of C-glycoside and C(3) branched glycoside derivatives, only β isomers were obtained. In case of C-glucopyranoside, axial isomer was obtained and in case of 2-deoxy-D-ribose derivative, α and β isomer were obtained.