4-Octulose Derivatives as Key Intermediates in a New and Short Synthesis of Polyhydroxyindolizidines
作者:Isidoro Izquierdo、María T. Plaza、Rafael Robles、Concepción Rodríguez、Antonio Ramírez、Antonio J. Mota
DOI:10.1002/(sici)1099-0690(199906)1999:6<1269::aid-ejoc1269>3.0.co;2-h
日期:1999.6
afforded the saturated nitriles 7 and 9, or the 1-amino-1,2,3-trideoxy-4-octulose derivatives 8 and 10, respectively. In an attempt to transform 6a into the appropriate polyhydroxylated branched-chain pyrrolidine 15, (5R,8S,9R,10S)-8,9,10-trihydroxy-1-aza-6-oxaspiro[4.5]decane, which was identified as its peracylated derivative 16, was isolated. Following an alternative synthetic strategy, partial hydrolysis
3与(氰基亚甲基)三苯基正膦在回流二氯甲烷或甲醇中的反应分别得到比例为约3:1和1:3的4a和4b的混合物。用呋喃类异构体 5 进行相同的反应,得到 6a 和 6b,(E)/(Z) 的比例分别约为 9:1 和 1:2。α,β-不饱和腈 4 和 6 与 10% Pd-C 或阮内镍的催化氢化得到饱和腈 7 和 9,或 1-氨基-1,2,3-三脱氧-4-辛酮糖衍生物 8和 10,分别。为了将 6a 转化为合适的多羟基支链吡咯烷 15,(5R,8S,9R,10S)-8,9,10-trihydroxy-1-aza-6-oxaspiro[4.5]decane,被鉴定为分离出其过酰化衍生物16。遵循替代的合成策略,