Asymmetric [4+2] cycloadditions employing 1,3-dienes derived from (R)-4-t-butyldimethyl-silyloxy-2-cyclohexen-1-one
β Scribed by Zhengmao Hua; Lei Chen; Yan Mei; Zhendong Jin
- Book ID
- 104096961
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- French
- Weight
- 915 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
β¦ Synopsis
1,3-Dienes derived from (R)-4-t-butyldimethylsilyloxy-2-cyclohexen-1-one react with activated dienophiles to form predominately (or sometimes exclusively) syn/endo products. These controlled [4+2] cycloadditions increase the asymmetric complexity from one asymmetric center in the starting material to five asymmetric centers in the products in a single step, and provide a powerful approach for the asymmetric synthesis of compounds containing the bicyclo[2.2.2]octanone carbon skeleton.
π SIMILAR VOLUMES
## Abstract Regioselective 1,3βdipolar cycloaddition of nitrilimines (generated in situ from dehydrohalogenation of the corresponding hydrazonoyl halides by the action of triethylamine) with 4βarylideneβ1βarylβ2βphenylβ1__H__βimidazolβ5(4__H__)βone **3** afforded the corresponding spiro[4,4]nonaβ2,
Thanks to its type-II dipole nature, we were able to demonstrate the higher reactivity of the SO 2 / CΒΌO syn-conformer for the uncatalyzed 1,3-dipolar cycloaddition of the 2-oxoethanenitrile oxide 2 derived from bornane-10,2-sultam to the symmetric 4,4'-disubstituted trans-stilbenes 3a -3i. The C(a)
The stereochemistry of the high-pressure (4+2)cycloaddition