Cetin Fatma, Yenil Nilgün, Yüceer Levent
Ege University, Faculty of Science, Chemistry Department, Bornova, Izmir 35100, Turkey.
Carbohydr Res. 2005 Dec 12;340(17):2583-9. doi: 10.1016/j.carres.2005.09.006. Epub 2005 Sep 22.
Sunlight-mediated photooxygenation of 3-O-acetyl and 3-O-methyl derivatives of 1,2-O-alkylidene-5(E)-eno-5,6,8-trideoxy-alpha-D-xylo-oct-1,4-furano-7-uloses (1a-e) in carbon tetrachloride solution gave stable 4,7-epidioxy derivatives in 4R (2a-e) and 4S (3a-e) configurations. The presence of an endo alkyl, on the 1,2-O-alkylidene group and its size, resulted in an increase of the yield of the 4S isomers. 3-O-acetyl derivatives yielded products as a mixture of C-7 anomers, whereas 3-O-methyl derivatives gave pure single stereoisomers.
在四氯化碳溶液中，1,2-O-亚烷基-5(E)-烯-5,6,8-三脱氧-α-D-木糖基-1,4-呋喃-7-酮糖（1a - e）的3-O-乙酰基和3-O-甲基衍生物经阳光介导的光氧化反应，生成了构型为4R（2a - e）和4S（3a - e）的稳定4,7-环氧二氧衍生物。1,2-O-亚烷基基团上内型烷基的存在及其大小导致4S异构体产率增加。3-O-乙酰基衍生物生成的产物为C-7端基异构体的混合物，而3-O-甲基衍生物则得到纯的单一立体异构体。
