3,6-trideoxy-alpha-D-glycero-hex-2-enopyranosid-4-ulose (1b) with trans-1-methoxy-3-tert-butyl-dimethylsilyloxy-1,3-butadiene is 3b (93%). Reaction of 3b wih sodium borohydride causes reduction of the C-4 carbonyl group only, but, with lithium aluminum hydride, further reactions occur which can be rationalized by fragmentation brought about by hydride cleavage on the silicon-oxygen bond, with simultaneous
Diels-Alder产物,由甲基2,3,6-苯
三甲氧基-α-D-
甘油-己基-2-烯
吡喃糖基-4-ulose(1b)与反式-1-甲氧基-3-叔丁基-二甲基甲
硅烷氧基反应-
1,3-丁二烯为3b(93%)。3b与
硼氢化钠的反应仅引起C-4羰基的还原,但与
氢化铝锂发生进一步的反应,这些反应可以通过
氢化物在
硅-氧键上裂解引起的碎裂而合理化,同时喷射出β-甲氧基与三价铝原子络合。由该断裂产生的烯酮也与
氢化铝锂进一步反应,并且产生几种产物。单独制备并受反应条件影响的假定中间体的行为支持了所提出的反应机理。“