A protected α-d-glucopyranosylacetaldehyde was converted by Wittig reaction with (thiazol-2-yl)carbonylmethylenetriphenyl phosphorane into the corresponding substituted 1-oxa-1,3-butadiene which by hetero-Diels-Alder reaction with ethyl vinyl ether afforded a mixture of two diastereoisomeric dihydropyran derivatives. These were separated by chromatography and the thiazol ring was transformed into an aldehyde group. Subsequent hydroboration afforded α-C-(1→3)-linked disaccharides containing 2-deoxyhexopyranoses of d- or l-configuration.
一种受保护的δ-d-
吡喃
葡萄糖基
乙醛通过与(
噻唑-2-基)羰基亚甲基三苯基
磷烷的 Wittig 反应转化为相应的取代 1-氧杂-
1,3-丁二烯,再通过与
乙烯基乙醚的杂 Diels-Alder 反应得到两种非对映异构的二氢
吡喃衍
生物混合物。这些衍
生物通过色谱法分离,
噻唑环转化为醛基。随后进行氢
硼化合,得到了含有 d 或 l 构型的 2-脱氧己
吡喃糖的 δ-C-(1→3)连接二糖。