Vincent W.-F. Tai

Facile syntheses of cyclopnellitol and its (1R,6S)-, (1R,2S,6S)-, (2S)-diastereoisomers from (–)-quinic acid

Cyclophellitol and its (1R,6S)-, (1R,2S,6S)-, (2S)-diastereoisomers are constructed from quinic acid involving a regioselective cyclic sulfate ring opening reaction, a regiospecific oxidative elimination, and an epoxidation reaction.

(–)-Quinic acid in organic synthesis. Part 4. Syntheses of cyclophellitol and its (1R, 6S)-, (2S)-, (1R, 2S, 6S)-diastereoisomers

Cyclophellitol 1 and its (1R, 6S)-, (2S)-, (1R, 2S, 6S)-diastereoisomers 2, 3 and 4 are constructed from quinic acid involving the following key steps: regioselective cyclic sulfate ring opening, regiospecific oxidative elimination and an epoxidation. Diastereoisomers 1, 2, 3 and 4 are characterized as their corresponding tetraacetates 5, 6, 7 and 8.

Synthesis and glycosidase-inhibitory activity of cyclophellitol analogues

Abstract The 6-deoxy-1,2-anhydro-analogues of cyclophellitol, 5 and 6, have been synthesised from diol 11 via a regioselective ring opening of the cyclic sulfate 15, an internal SN2 reaction and hydrogenolysis. Compounds 5, 6, cyclophellitol 1 and its diastereoisomers 2–4 were assayed for inhibitory activity against six glycosidases. Oxirane 5 was shown to possess activity towards both β-mannosidase (A. oryzae) and β-glucosidase (almonds) but 6 showed no significant inhibitory activity.

Gonibutenolides A and B: serendipitous syntheses, relative and absolute configuration

The relative and absolute stereochemistries of natural goniobutenolides A and B are established as 1 and 2 respectively by short syntheses of them and their 8-epimers.