(2) with methoxycarbonyl-methylene triphenylphosphorane was accompanied by spontaneous cyclization to generate 3 stereospecifically. Deprotection of 5-OH followed by mild base hydrolysis and cyclization with Py-Ac2O-DBU then yielded 4,7-anhydro-5,6-isopropylidene-4(S), 5(S), 6(R), 7(R)-tetrahydroxyoxocan-2-one (5) in good overall yield.
摘要 2,3-O-异亚丙基-5-O-panisyldiphenylmethyl-β-D-
呋喃核糖(2)与甲氧基羰基-亚甲基
三苯基膦的Wittig反应伴随自发环化生成3立体特异性。5-OH 脱保护,然后用 Py-Ac2O-
DBU 进行温和碱
水解和环化,然后产生 4,7-脱
水-5,6-异亚丙基-4(S), 5(S), 6(R), 7(R) )-tetrahydroxyoxocan-2-one (5) 的总产率良好。