Preparative synthesis of C-(alpha-D-glucopyranosyl)-alkenes and -alkadienes: Diels-Alder reaction

Thermal and Lewis acid promoted intramolecular Diels–Alder reaction of furanose tethered 1,3,9-decatriene systems: a synthetic and computational investigation

The intramolecular Diels–Alder (IMDA) reaction of furanose tethered 1,3,9-decatrienes (4a–4r) was investigated under thermal conditions and in the presence of a Lewis acid.

StereoselectiveC-Glycosylation Reactions of Pyranoses: The Conformational Preference and Reactions of the Mannosyl Cation

A systematic study of C-glycosylations of acetals related to mannose and other pyranoses was conducted. The C-5 alkoxyalkyl group provides only a modest influence on stereoselectivity. On the other hand, studies of pentopyranoses bearing alkoxy groups at C-2, C-3, and C-4 showed that the alkoxy groups exerted powerful influences on selectivity. In the case of mannose, the high alpha selectivity observed with C-mannosylation was reversed to high beta selectivity if the C-5 alkoxyalkyl group were removed. An analysis of the conformational preferences of the intermediate oxocarbenium ions, including the mannosyl cation, as well as consideration of steric effects that develop in the transition states for nucleophilic attack provide explanations for these phenomena.