Among the three types of reagents from PhMgX (X=Br, Cl) and CuCN for phenylation of 4-cyclopentene-1,3-diol monoacetate, PhMgCl/CuCN (cat.) and Ph 2 Cu(CN)(MgCl) 2 in THF afforded the trans-1,4-isomer efficiently (82-87% yields, 91-93% regioselectivity). Similarly, o-and p-RC 6 H 4 MgCl (R=Me, OMe,
3-TMS-cyclopentene-1 a new reagent for the synthesis of cyclopentene derivatives
β Scribed by Iwao Ojima; Miyoko Kumagai; Yuji Miyazawa
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- French
- Weight
- 200 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
Recently, allyltrimethylsilane has been shown to be a good reagent for allylation of acyl halides 1 or carbonyl compounds 2 in the presence of Lewis acid. Now we wish to report here a new and convenient route to cyclopentene derivatives using the reactions of 3-trimethylsilylcyclopentene-1, a cyclic allylsilane, with various carbonyl compounds. 3-TMS-cyclopentene-1 is a useful new reagent for the regiospecific introduction of cyclopentene skeleton in organic synthesis, which can easily be prepared by the hydrosilylation of cyclopentadiene.
π SIMILAR VOLUMES
Ketenes bearing a-carbanion-stabilizing substituents are useful synthetic intermediates 192 offering the interesting possibility of effecting the position-and stereospecific addition of two carbon-chains to an olefinic substrate (scheme 1).