(+/-)-5-Ethyl-2-exo-methyl-4-methylene-6,8-dioxabicyclo<3.2.1>octane

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 氧杂环己烷
• 英文名称: (+/-)-5-Ethyl-2-exo-methyl-4-methylene-6,8-dioxabicyclo<3.2.1>octane
• 英文别名: (1S,2S,5R)-5-ethyl-2-methyl-4-methylidene-6,8-dioxabicyclo[3.2.1]octane
• 化学式: C₁₀H₁₆O₂
• 分子量: 168.236
• InChiKey: VPMBOMGULZQEQN-FXBDTBDDSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.7
• 重原子数：
  12
• 可旋转键数：
  1
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.8
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  (+/-)-5-Ethyl-2-exo-methyl-4-methylene-6,8-dioxabicyclo<3.2.1>octane 在 palladium on activated charcoal 、 三氟乙酸 氢气 作用下， 反应 48.0h， 生成 (-)-δ-multistriatin
  参考文献：
  名称：

  The First Stereoselective Synthesis of Racemic .beta.-Multistriatin: A Pheromone Component of the European Elm Bark Beetle Scolytus multistriatus (Marsh.)

  摘要：

  The first stereoselective synthesis of racemic beta-multistriatin (4), a component of the pheromone of the European elm bark beetle Scolytus multistriatus (Marsh.), is described. Potassium glycerate (23) is alkylated with 2-bromopentanone (26) in the presence of the phase transfer catalyst TDA-1 to form the acyloin ester 29 in 75% yield. After trimethylsilylation of 29, intramolecular acetalization of the product 30 in the presence of catalytic amounts of trimethylsilyl triflate and perchloric acid affords a mixture of diastereomers of the bicyclic lactone 28 in 65% yield. Reduction of 28 with LiAlH4 gives the cis-disubstituted dioxolane diol 34 in 82% yield. Oxidation of both the primary and secondary hydroxy groups present in 34 by a modified Swern oxidation affords the keto aldehyde 35 in 61% yield. The change of the reagent ratio of oxalyl chloride:DMSO:NEt(3) from 1.1:2.4:5 to 1.2:1.2:3 and a nonaqueous workup procedure are crucial for the success of this oxidation. Intramolecular aldol condensation of 35 catalyzed by triethylammonium chloride affords the aldol 38. Acetylation of 38 and pyrolytic distillation give the bicyclic enone 37. Oxidation of 34, aldol reaction, and formation of the enone 37 can be combined in a one-pot procedure to give an overall yield of 21%. 1,4-Addition of lithium dimethylcuprate to the enone 37 affords ketone 36 with the methyl group exclusively in the axial position. After Wittig methylenation of 36, the olefin 40 is obtained in 76% yield. Catalytic hydrogenation of 40 with PtO2 gives a 92:8 mixture of beta- and delta-multistriatin in 85% yield. Acid-catalyzed epimerization of 4 affords delta-multistriatin (5). Some of the compounds prepared (28, 36, 37, and 40) are of interest as multistriatin analogues. Olefin 40 is also a valuable storage form for the unstable beta-multistriatin (4).

  DOI：

  10.1021/jo00121a034
• 作为产物：
  描述：

  (+/-)-r-2-Acetyl-c-4-formyl<1,3>dioxolane 在 三乙胺盐酸盐 4-二甲氨基吡啶 、 copper(I) bromide dimethylsulfide complex 、 potassium tert-butylate 、 三乙胺 作用下， 以 二氯甲烷 为溶剂， 反应 56.08h， 生成 (+/-)-5-Ethyl-2-exo-methyl-4-methylene-6,8-dioxabicyclo<3.2.1>octane
  参考文献：
  名称：

  The First Stereoselective Synthesis of Racemic .beta.-Multistriatin: A Pheromone Component of the European Elm Bark Beetle Scolytus multistriatus (Marsh.)

  摘要：

  The first stereoselective synthesis of racemic beta-multistriatin (4), a component of the pheromone of the European elm bark beetle Scolytus multistriatus (Marsh.), is described. Potassium glycerate (23) is alkylated with 2-bromopentanone (26) in the presence of the phase transfer catalyst TDA-1 to form the acyloin ester 29 in 75% yield. After trimethylsilylation of 29, intramolecular acetalization of the product 30 in the presence of catalytic amounts of trimethylsilyl triflate and perchloric acid affords a mixture of diastereomers of the bicyclic lactone 28 in 65% yield. Reduction of 28 with LiAlH4 gives the cis-disubstituted dioxolane diol 34 in 82% yield. Oxidation of both the primary and secondary hydroxy groups present in 34 by a modified Swern oxidation affords the keto aldehyde 35 in 61% yield. The change of the reagent ratio of oxalyl chloride:DMSO:NEt(3) from 1.1:2.4:5 to 1.2:1.2:3 and a nonaqueous workup procedure are crucial for the success of this oxidation. Intramolecular aldol condensation of 35 catalyzed by triethylammonium chloride affords the aldol 38. Acetylation of 38 and pyrolytic distillation give the bicyclic enone 37. Oxidation of 34, aldol reaction, and formation of the enone 37 can be combined in a one-pot procedure to give an overall yield of 21%. 1,4-Addition of lithium dimethylcuprate to the enone 37 affords ketone 36 with the methyl group exclusively in the axial position. After Wittig methylenation of 36, the olefin 40 is obtained in 76% yield. Catalytic hydrogenation of 40 with PtO2 gives a 92:8 mixture of beta- and delta-multistriatin in 85% yield. Acid-catalyzed epimerization of 4 affords delta-multistriatin (5). Some of the compounds prepared (28, 36, 37, and 40) are of interest as multistriatin analogues. Olefin 40 is also a valuable storage form for the unstable beta-multistriatin (4).

  DOI：

  10.1021/jo00121a034

文献信息

• The First Stereoselective Synthesis of Racemic .beta.-Multistriatin: A Pheromone Component of the European Elm Bark Beetle Scolytus multistriatus (Marsh.)
  作者：Ulrich Berens、Hans-Dieter Scharf

  DOI：10.1021/jo00121a034

  日期：1995.8

  The first stereoselective synthesis of racemic beta-multistriatin (4), a component of the pheromone of the European elm bark beetle Scolytus multistriatus (Marsh.), is described. Potassium glycerate (23) is alkylated with 2-bromopentanone (26) in the presence of the phase transfer catalyst TDA-1 to form the acyloin ester 29 in 75% yield. After trimethylsilylation of 29, intramolecular acetalization of the product 30 in the presence of catalytic amounts of trimethylsilyl triflate and perchloric acid affords a mixture of diastereomers of the bicyclic lactone 28 in 65% yield. Reduction of 28 with LiAlH4 gives the cis-disubstituted dioxolane diol 34 in 82% yield. Oxidation of both the primary and secondary hydroxy groups present in 34 by a modified Swern oxidation affords the keto aldehyde 35 in 61% yield. The change of the reagent ratio of oxalyl chloride:DMSO:NEt(3) from 1.1:2.4:5 to 1.2:1.2:3 and a nonaqueous workup procedure are crucial for the success of this oxidation. Intramolecular aldol condensation of 35 catalyzed by triethylammonium chloride affords the aldol 38. Acetylation of 38 and pyrolytic distillation give the bicyclic enone 37. Oxidation of 34, aldol reaction, and formation of the enone 37 can be combined in a one-pot procedure to give an overall yield of 21%. 1,4-Addition of lithium dimethylcuprate to the enone 37 affords ketone 36 with the methyl group exclusively in the axial position. After Wittig methylenation of 36, the olefin 40 is obtained in 76% yield. Catalytic hydrogenation of 40 with PtO2 gives a 92:8 mixture of beta- and delta-multistriatin in 85% yield. Acid-catalyzed epimerization of 4 affords delta-multistriatin (5). Some of the compounds prepared (28, 36, 37, and 40) are of interest as multistriatin analogues. Olefin 40 is also a valuable storage form for the unstable beta-multistriatin (4).