Selective Deoxygenation of Allylic Alcohol: Stereocontrolled Synthesis of Lavandulol
作者:Hee Jin Kim、Liang Su、Heejung Jung、Sangho Koo
DOI:10.1021/ol200779y
日期:2011.5.20
Selective deoxygenation of allylicalcohol can be successfully carried out by the formation of alkoxyalkyl ether (EE or MOM), followed by Pd(dppe)Cl2-catalyzed reduction with LiBHEt3. (+)-S-Lavandulol has been efficiently synthesized by the application of this protocol to the diol derived from the Pb(OAc)4-promoted oxidative ring-opening of (−)-R-carvone. This deoxygenationmethod is general and selective
通过形成烷氧基烷基醚(EE或MOM),然后用LiBHEt 3催化Pd(dppe)Cl 2催化还原,可以成功地进行烯丙醇的选择性脱氧。通过将该方案应用于衍生自Pb(OAc)4促进的(-)- R-香芹酮的氧化开环的二醇,已有效地合成了(+)- S - Lavandulol。该脱氧方法对烯丙基醇是通用的和选择性的。
Brønsted Acid Enabled Nickel-Catalyzed Hydroalkenylation of Aldehydes with Styrene and its Derivatives
enabled nickel‐catalyzed hydroalkenylation of aldehydes and styrenederivatives has been developed. The Brønsted acid acts as a proton shuttle to transfer a proton from the alkene to the aldehyde, thereby leading to an economical and byproduct‐free coupling. A series of synthetically useful allylic alcohols were obtained through one‐step reactions from readily available styrenederivatives and aliphatic
A facile enantioselective route to highly functionalized α,β-unsaturated -δ-lactones has allowed for the synthesis of (+)-isoaltholactone in 6.4% overall yield from furylmethanol. This approach derived its asymmetry by applying Sharpless kinetic resolution on racemic 2-furylmethanol. The resulting pyranone was produced in high enantioexcess and was stereoselectively transformed into (+)-isoaltholactone
Convergent synthesis of conjugated 1,2-disubstituted E-allylic alcohols from two aldehydes and methylenetriphenylphosphorane
作者:David M. Hodgson、Rosanne S. D. Persaud
DOI:10.1039/c2ob26346g
日期:——
β-Lithiooxyphosphonium ylides, made in situ from an aldehyde and methylenetriphenylphosphorane, react with a second aldehyde to form E-allylic alcohols. α-Branching and α,β-unsaturation in the second aldehyde, together with the lack of further substitution on the phosphorane carbon play important roles in selectivity. A range of these aldehydes, in addition to aromatic aldehydes as the second aldehyde also provided synthetically useful access to E-allylic alcohols.
A new and efficient reaction sequence between 2-furylcarbinols, anilines, and alpha-haloamides has been developed to afford highly functionalized cyclopenta[b]piperazinones. This transformation was accomplished through an aza-Piancatelli cyclization/azaoxyallyl cation trapping with a complete control of the diastereoselectivity.