The Diels-Alderreactions of a variety of hexopyranosides carrying an acrylic ester with cyclopentadiene were examined. Some acrylic esters provided the cycloaddition products carrying a norbornene carboxylate with a high level of diastereoselectivity. Plausible mechanisms are presented for the cases of a 4-O-acryloyl-6-deoxy-α-D-glucopyranosidic and 2-O-acryloyl-α-D-glucopyranosidic substrates. By
考察了各种带有丙烯酸酯的六吡喃糖苷与环戊二烯的Diels-Alder反应。一些丙烯酸酯提供了带有降冰片烯羧酸盐的非对映选择性高的环加成产物。合理的机制被呈现为的情况下,4- ø -丙烯酰基-6-脱氧-α- d -glucopyranosidic和2- ö -丙烯酰基α- d -glucopyranosidic基材。通过从加合物中还原性除去碳水化合物模板,获得了富含2 S或2 R的5-降冰片烯-2-甲醇。