Radical-mediated hydroxyalkylation of α,β-unsaturated esters
摘要:
The radical-mediated hydroxyalkylation of alpha,beta-unsaturated esters with alkyl iodides, trialkylborane, water and KF in THF gave the corresponding alpha-hydroxy esters. The synthetic advantage of the method was demonstrated by a short-step total synthesis of (+/-)-tanikolide. (c) 2005 Elsevier Ltd. All rights reserved.
We have presented two facile four-step syntheses of (±)-tanikolide from ethyl 2-oxocyclopentanecarboxylate. The overall chemical yields of the two sequences reached as high as 76 and 85%, respectively. The first strategy involved alkylation, Baeyer–Villiger reaction, saponification, and reduction/lactonization. The second approach for synthesizing tanikolide took advantage of the same intermediate
We report a concise synthesis of tanikolide 1, which was obtained from ethyl2-oxocyclopentanecarboxylate in four steps: alkylation, Baeyer–Villiger reaction, saponification, and reduction/lactonization, in 70% overall yield. Our strategy should be suitable for the preparation of 1 in multigram or larger quantities. The net result of the last two steps (i.e. saponification and reduction/lactonization)
Syntheses of 5-Hexadecanolide, 6-Acetoxy-5-hexadecanolide and Tanikolide
作者:Meng-Yang Chang、Chien-Lun Lin、Shui-Tein Chen
DOI:10.1002/jccs.200100112
日期:2001.8
Total syntheses of 5-hexadecanolide (1), 6-acetoxy-5-hexadecanolide (2) and tanikolide (3) are described. 1-Bromoundecane (4) and 5-benzyl-1-pentanal (5) were chosen as starting materials. Wittig olefination and Grignard addition 4 and 5 afforded the 16-carbon skeleton, which under went a series of functional group transformations to give δ-lactonederivatives 1, 2 and 3.
A total synthesis of (::E)tanikolide I is described. The six-membered lactone moiety of the title compound was completed through oxidation of alpha,delta-dihydroxyl compound by PDC.