Easy Access to Aroma Active Unsaturated γ-Lactones by Addition of Modified Titanium Homoenolate to Aldehydes
作者:Eric Frerot、Alain Bagnoud
DOI:10.1021/jf104711x
日期:2011.4.27
The homo-Reformatsky reaction, in which a metalhomoenolate of an ester is added to an aldehyde, was adapted to produce γ-lactones from unsaturated, enolizable aldehydes. By use of titaniumhomoenolate, 11 different γ-lactones were synthesized in one step with moderate to good yields from readily available aldehydes. In particular, this procedure allowed the rapid preparation of a series of C12 unsaturated
Intramolecular [4+2]-cycloadditions of nitroalkenes with olefins. 2
作者:Scott E. Denmark、Young-Choon Moon、Christopher J. Cramer、Michael S. Dappen、C.B.W. Senanayake
DOI:10.1016/s0040-4020(01)89054-2
日期:1990.1
The intramolecular [4+2]-cycloadditions of di- and trisubstituted nitroalkenes with unactivated olefins are described. The cycloadditions proceed readily at low temperatures in the presence of SnCl4. The reactions are shown to be stereospecific in the preservation of dienophile configuration in the product. The configuration of the heterodiene controls the stereochemistry of the ring fusion but the