Synthesis of anomerically pure vinyl sulfone-modified pent-2-enofuranosides and hex-2-enopyranosides: a group of highly reactive Michael acceptors for accessing carbohydrate based synthons
作者:Aditya Kumar Sanki、Tanmaya Pathak
DOI:10.1016/s0040-4020(03)01059-7
日期:2003.9
from the derivatives of d-xylose. For the synthesis of α- and β-anomers of vinyl sulfone-modified hex-2-enopyranosides, a d-glucose derivative was selected over a d-allose derivative as the starting material because the former almost exclusively produced the required methyl pyranosides whereas the latter produced a mixture. All sulfides were converted to vinyl sulfone-modified carbohydrates by the sequential
乙烯基砜改性的戊-2-烯呋喃糖苷的苄基或三苯甲基保护的α-和β-端基异构体的合成已通过适当掩蔽的甲基α - lyxo呋喃糖基环氧化合物或甲基β-核糖呋喃糖基环氧化合物的开环而引发。或通过苄基保护的3- O-甲苯磺酰基木糖呋喃糖苷和3- O-甲磺酰基核糖呋喃糖苷中离去基团的亲核取代被p-硫代甲酚。在后一组原料的情况下,α-和β-甲基糖苷仅由d-木糖的衍生物以几乎相等的比例形成。对于乙烯基砜改性的hex-2-enopyranosides的α和β端基异构体的合成,选择d-葡萄糖衍生物而不是d-阿洛糖衍生物作为起始原料,因为前者几乎只能生产所需的甲基吡喃糖苷,而后者产生了混合物。通过顺序应用氧化,甲磺酰化和碱诱导的消除反应,将所有硫化物均转化为乙烯基砜改性的碳水化合物。