CARBOHYDRATES AS CHIRAL TEMPLATES - STEREOSELECTIVE DIELS-ALDER SYNTHESIS WITH DIENES OF DIFFERING REACTIVITY

With appropriate variation of the Lewis acidity and temperature, dienes of quite differing reactivity are transformed stereoselectively to either their (R)- or (S)-configurated Diels-Alder adducts using acrylates linked to O-3 of either dihydroglucal 1 (1,5-anhydro-2-deoxy-4,6-di-O-pivaloyl-D-arabino-hexitol) or dihydrorhamnal 2 (1,5-anhydro-2,6-dideoxy-4-O-pivaloyl-L-arabino-hexitol), respectively, as the chiral templates.