Stereochemical aspects of the formation of diastereoisomeric 3-acetyl-2-(polyacetoxyalkyl)-5-phenyl-2,3-dihydro-1,3,4-oxadiazoles
作者:László Somogyi
DOI:10.1016/0008-6215(88)84088-6
日期:1988.10
arabino -(tetra-acetoxybutyl)]- [(−)- and (+)- 4a , (−)- 4b ] and 3-acetyl-2-[ d - manno -(penta-acetoxypentyl)]-5-phenyl-2,3-dihydro-1,3,4-oxadiazoles [(+)- 4d ] via cyclisation of the corresponding ( O -acetylated) aldose benzoylhydrazones ( 2a,b,d ) under acetylating conditions is described. The stereochemical aspects of the formation of C-2 epimeric oxadiazolines [ e.g. , (−)- and (+)- 4a ] are discussed
摘要d-和l -3-乙酰基-2- [阿拉伯-(四乙酰氧基丁基)]-[(-)-和(+)-4a,(-)-4b]和3-乙酰基-2-的合成[d-manno-(penta-acetoxypentyl)]-5-phenyl-2,3-dihydro-1,3,4-oxadiazoles [(+)-4d]通过相应的(O-乙酰化)醛糖苯甲酰hydr(2a描述了在乙酰化条件下的(b,d)。基于旋光度和核磁共振数据,讨论了C-2差向异构恶二唑啉[例如,(-)-和(+)-4a]形成的立体化学方面。发现甲基乙二醛双(苯甲酰基hydr)(8)的乙酰化得到非对映异构的1,3,4-恶二唑啉(12a和12b),而不是文献中要求的双(乙酰苯甲酰hydr)9。