(4R*,5S*,6R*)-3-benzyl-5-methoxycarbonyl-4,6-dimethyl-2-(4-nitrophenyl)tetrahydro-1,3-oxazine | 130655-60-6

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: (4R*,5S*,6R*)-3-benzyl-5-methoxycarbonyl-4,6-dimethyl-2-(4-nitrophenyl)tetrahydro-1,3-oxazine
• 英文别名: 4,5-cis-5,6-trans-5-(methoxycarbonyl)-4,6-dimethyl-2-(4-nitrophenyl)-3-benzyltetrahydro-1,3-oxazine；methyl (4R,5S,6R)-3-benzyl-4,6-dimethyl-2-(4-nitrophenyl)-1,3-oxazinane-5-carboxylate
• CAS: 130655-60-6
• 化学式: C₂₁H₂₄N₂O₅
• 分子量: 384.432
• InChiKey: OHHGCTPAHQQBOP-GKDLUCGISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.6
• 重原子数：
  28
• 可旋转键数：
  5
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.38
• 拓扑面积：
  84.6
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为产物：
  描述：

  (E,Z)-methyl 2-(1-(((1,1-dimethylethyl)dimethylsilyl)oxy)ethyl)-2-butenoate 在 四丁基氟化铵 作用下， 以 四氢呋喃 、 甲醇 、 苯 为溶剂， 反应 68.0h， 生成 (4R*,5S*,6R*)-3-benzyl-5-methoxycarbonyl-4,6-dimethyl-2-(4-nitrophenyl)tetrahydro-1,3-oxazine
  参考文献：
  名称：

  A Simple Route to .alpha.-Substituted-.beta.-Amino Ester Precursors of Carbapenem Antibiotics

  摘要：

  A three-step process is presented for the preparation of alpha-substituted-beta-amino esters which can serve as precursors to a key intermediate in carbapenem synthesis. The pivotal reaction in this sequence involves a highly diastereoselective conjugate addition reaction. Two series of alkenoates bearing a stereogenic substituent attached to C2 were prepared and their conjugate addition reactions with benzylamine studied under several different sets of conditions. Conjugate addition of benzylamine to alkenoates 7a and 7d, in methanol at room temperature, gave adducts 8a and Sd with virtually complete anti-diastereoselectivity. These two beta-amino esters bear the correct relative stereochemistry and side chain to serve as precursors for carbapenem antibiotic synthetic intermediates. The role of the allylic substituents of the alkenoates 7a-e in determining the stereochemical outcome of these additions is discussed. These conjugate additions were explored further by the preparation and conjugate addition reactions of the alpha,beta-disubstituted alkenoates 15a and 15b. It was found that the presence of a beta-substituent led to a dramatic reduction in yield although the same anti-diastereoselectivity was maintained. The relative stereochemistry of the adducts was established by examination of the relevant coupling constants in the H-1 NMR spectra of their tetrahydro-1,3-oxazine derivatives.

  DOI：

  10.1021/jo00125a043

文献信息

• Stereodivergent synthesis of the enolates of a β-amino ester by using lithium N-benzyltrimethylsilylamide
  作者：Naoki Asao、Tadao Uyehara、Yoshinori Yamamoto

  DOI：10.1016/s0040-4020(01)85581-2

  日期：1990.1

  Highly stereoselective generation of both Z- and E-enolates (1 and 3)2 is accomplished by the conjugate addition of lithium N-benzyltrimethylsilylamide (LSA) to methyl crotonate. The alkylation with alkyl halides and aldol condensation with aldehydes via 1 and 3 are studied. The alkylation of 3 produces moderate to good syn selectivity, while that of 1 gives no selectivity. The aldol condensation of

  Z-和E-烯酸酯（1和3）2的高度立体选择性生成是通过将N-苄基三甲基甲硅烷基酰胺锂（LSA）共轭添加到巴豆酸甲酯中实现的。研究了烷基卤化物的烷基化和醛与醛的醛缩合反应（通过1和3）。3的烷基化产生中等至良好的顺选择性，而1的烷基化则没有选择性。1的醇醛缩合主要提供抗-同分异构体（11），而3的醇醛缩合主要提供顺-反异构体（14）。