Showing papers by "J. Cristobal Lopez published in 1992"
TL;DR: Ferrier-type reactions can now be carried out under non-acidic conditions by treating 3-n-pentenoyl glycals with iodonium dicollidinium perchlorate to afford 2,3-unsaturated disaccharides in fairly good yields.
Abstract: Ferrier-type reactions can now be carried out under non-acidic conditions by treating 3-n-pentenoyl glycals with iodonium dicollidinium perchlorate whereupon the terminal double bond is chemoselectively activated to furnish an allylic oxo-carbenium ion which reacts at the anomeric position with monosaccharide alcohols to afford 2,3-unsaturated disaccharides in fairly good yields.
38 citations
12 citations
TL;DR: In this article, the authors propose to add benzenethiol to carbohydrate derived hex-2-enono-δ-lactones to obtain 3-phenylthio derivatives that, on treatment with tributyltin hydride and AIBN, undergo an efficient radical cyclization to give highly functionalized cyclohexanes and cyclopentanes.
Abstract: Conjugated addition of benzenethiol, under mild conditions, to carbohydrate derived hex-2-enono-δ-lactones, substituted at C-6 or C-7 with an electron-rich insaturation, affords 3-phenylthio derivatives that, on treatment with tributyltin hydride and AIBN (azoisobutyronitrile), undergo an efficient radical cyclization to give highly functionalized cyclohexanes and cyclopentanes.
10 citations
TL;DR: In this article, a stereospecific route to highly functionalized 2,5-disubstituted tetrahydrofuran derivatives from readily available 6-O-silylated-hex-2-enono-δ-lactones is reported.
6 citations
TL;DR: Avermectin B1a Δ4,4a, 2, and its bioactivity evaluated in this article, where the key step of the transformation is the reduction of an intermediate allylic radical with nBu3SnH.
3 citations
TL;DR: Avermectin B1a Δ4,4a, 2, and its bioactivity evaluated in this article, where the key step of the transformation is the reduction of an intermediate allylic radical with nBu3SnH.
Abstract: Avermectin B1a Δ4,4a, 2, has been obtained from avermectin B1a, 1, and its bioactivity evaluated. The key step of the transformation is the reduction of an intermediate allylic radical with nBu3SnH.