E,E,Z-10-hydroxyoxacycloeicosa-3,5,7-trien-2-one | 1115861-26-1

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 大环内酯类和类似物
• 英文名称: E,E,Z-10-hydroxyoxacycloeicosa-3,5,7-trien-2-one
• 英文别名: (3E,5E,7Z)-10-hydroxy-1-oxacycloicosa-3,5,7-trien-2-one
• CAS: 1115861-26-1
• 化学式: C₁₉H₃₀O₃
• 分子量: 306.445
• InChiKey: AKYKLTSGPKNTNT-IVAUWPBFSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.8
• 重原子数：
  22
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.63
• 拓扑面积：
  46.5
• 氢给体数：
  1
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  syn-8,20,22-trioxabicyclo[17.3.1]tricosa-3,5-dien-7,21-dione 在 1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下， 以 四氢呋喃 为溶剂， 以74%的产率得到E,E,Z-10-hydroxyoxacycloeicosa-3,5,7-trien-2-one
  参考文献：
  名称：

  Biomimetic Transannular Oxa-Conjugate Addition Approach to the 2,6-Disubstituted Dihydropyran of Laulimalide Yields an Unprecedented Transannular Oxetane

  摘要：

  2,6-Disubstituted dihydropyrans are a common feature in many bioactive polyketides, including the anticancer marine polyketide laulimalide. While much of the uncharacterized biosynthetic pathway for laulimalide can be confidently postulated, the biosynthetic origins of the trans 2,6-disubstituted dihydropyran cannot. We hypothesize that a transannular oxa-conjugate addition in a macrocyclic laulimalide precursor could be the origin of the 2,6-dihydropyran. To test this hypothesis, we constructed a model containing the key functional groups for oxa-conjugate addition-mediated dihydropyran formation. Under acid-mediated conditions, the model under went regiospecific oxa-conjugate addition producing a stable trans oxetane as the only regioisomer. The desired, more stable dihydropyran was not detected. This unprecedented regiospecificity is unexpected due to the ring strain of the oxetane and the anticipated facile ring opening retro-oxa-conjugate addition. The oxetane is stable to acid and basic conditions, as are a number of literature acyclic oxetanes that could undergo similar retro-oxa-conjugate addition. While the source of the oxetane kinetic stability is yet to be characterized, it may enable general oxetane construction via oxa-conjugate addition. The more stable dihydropyran regioisomer could not be generated due to poor geometrical orbital alignment and hard-soft incompatibility between the hard oxygen nucleophile and the soft activated polyenoate electrophile. These factors disfavor the breaking of conjugation by oxa-conjugate addition. Based on these results we propose that dihydropyran formation does not occur on completed polyketide macrocycles as we had proposed but rather during polyketide biosynthesis on the growing polyketide chain.

  DOI：

  10.1021/jo8023494