(2R,5S)-2-(tert-Butyl)-5-methyl-1,3-dioxan-4-on

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二恶烷
• 英文名称: (2R,5S)-2-(tert-Butyl)-5-methyl-1,3-dioxan-4-on
• 英文别名: 1,3-Dioxan-4-one, 2-(1,1-dimethylethyl)-5-methyl-, (2s-cis)-；(2R,5S)-2-tert-butyl-5-methyl-1,3-dioxan-4-one
• 化学式: C₉H₁₆O₃
• 分子量: 172.224
• InChiKey: IDAKACQLSWKCND-POYBYMJQSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  12
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.89
• 拓扑面积：
  35.5
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  (2R)-2-(tert-butyl)-1,3-dioxan-4-one 、 碘甲烷 在 正丁基锂 、 二异丙胺 作用下， 以 四氢呋喃 、 正己烷 为溶剂， 反应 4.0h， 以46%的产率得到(2R,5S)-2-(tert-Butyl)-5-methyl-1,3-dioxan-4-on
  参考文献：
  名称：

  ?-Alkylierung von ?-Hydroxycarbons�uren �ber 1,3-Dioxan-4-on-Enolate

  摘要：

  Highly Diastereoselective α‐Alkylation of β‐Hydroxycarboxylic Acids Through Lithium Enolates of 1,3‐Dioxan‐4‐onesFrom serine, β‐hydroxyisobutyric acid (‘Roche’ acid) and β‐hydroxybutyric acid, the dioxanones 1–6 were prepared. The generation of the enolates of type I with LDA at −75° and alkylation gave products with trans‐configuration whereas protonation of the 5‐methyl‐substituted enolate allowed access to the cis‐configurated β‐hydroxybutyric‐acid derivative 12. Hydrolysis gave the free β‐hydroxy acids of ‘syn’‐and ‘anti’‐configuration. Alkylation of the 6‐unsubstituted dioxanones 1 and 3 yielded predominantly products resulting from attack in the cis‐position of the t‐Bu group. The ‘reactive’ conformation of the enolates involved is tentatively derived from the product configuration. The selectivity of the alkylation is also discussed in terms of the results of an ab‐initio calculation on the enolates M–P.

  DOI：

  10.1002/hlca.19880710527

文献信息

• ?-Alkylierung von ?-Hydroxycarbons�uren �ber 1,3-Dioxan-4-on-Enolate
  作者：J�rg Zimmermann、Dieter Seebach、Tae-Kyu Ha

  DOI：10.1002/hlca.19880710527

  日期：1988.8.10

  Highly Diastereoselective α‐Alkylation of β‐Hydroxycarboxylic Acids Through Lithium Enolates of 1,3‐Dioxan‐4‐onesFrom serine, β‐hydroxyisobutyric acid (‘Roche’ acid) and β‐hydroxybutyric acid, the dioxanones 1–6 were prepared. The generation of the enolates of type I with LDA at −75° and alkylation gave products with trans‐configuration whereas protonation of the 5‐methyl‐substituted enolate allowed access to the cis‐configurated β‐hydroxybutyric‐acid derivative 12. Hydrolysis gave the free β‐hydroxy acids of ‘syn’‐and ‘anti’‐configuration. Alkylation of the 6‐unsubstituted dioxanones 1 and 3 yielded predominantly products resulting from attack in the cis‐position of the t‐Bu group. The ‘reactive’ conformation of the enolates involved is tentatively derived from the product configuration. The selectivity of the alkylation is also discussed in terms of the results of an ab‐initio calculation on the enolates M–P.