Preparation of medium- and large-ring lactones. SmI2-induced cyclization of ω-(α-bromoacyloxy) aldehydes
✍ Scribed by Takanori Tabuchi; Kisa Kawamura; Junji Inanaga; Masaru Yamaguchi
- Book ID
- 104218023
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- French
- Weight
- 137 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
W-Bromoacetoxy-and W-(a-bromopropionyloxy) aldehydes were cyclized by SmI2 giving 8-to 14-membered ring @-hydroxy lactones in excellent yields. Recent synthetic elaborations in the field of macrolides have prompted the development of numerous useful lactonization methods. 2) However, few of them are effective for the formation of medium-ring lactones, especially for 8-and g-membered rings. 3) Therefore, indirect ring expansion methods such as Baeyer-Villiger oxidation of cyclic ketones 4) or oxidative cleavage of C-C double bond of bicyclic enol ethers 5) have so far been adopted to get such strained lactones