Diastereoselective Mukaiyama and Free Radical Processes for the Synthesis of Polypropionate Units
摘要:
Reported herein is the synthesis of 8 out of 16 polypropionates derived from our propionate units. A new strategy involving a stereoselective Mukaiyama aldol reaction followed by a stereoselective free-radical-based hydrogen transfer, both under Lewis acid control, is used. Of particular interest is the remarkable reactivity of (i-PrO)TiCl3 in this context to give only the 3,4-anti bromoesters.
Diastereoselective Mukaiyama and Free Radical Processes for the Synthesis of Polypropionate Units
摘要:
Reported herein is the synthesis of 8 out of 16 polypropionates derived from our propionate units. A new strategy involving a stereoselective Mukaiyama aldol reaction followed by a stereoselective free-radical-based hydrogen transfer, both under Lewis acid control, is used. Of particular interest is the remarkable reactivity of (i-PrO)TiCl3 in this context to give only the 3,4-anti bromoesters.
Stereopentads Derived from a Sequence of Mukaiyama Aldolization and Free Radical Reduction on α-Methyl-β-alkoxy Aldehydes: A General Strategy for Efficient Polypropionate Synthesis
aldolization with enoxysilane 24 followed by a hydrogen transfer reaction. Recent advancements concerning these reactions are described, and novel key intermediates are characterized in the aldol step. The synthesis of C(1)−C(11) fragment 60 of zincophorin, which contains a synthetically challenging stereopentad unit, is described attesting the usefulness of our strategy.
Reported herein is the total synthesis of zincophorin methylester, a polyketide ionophore. Of particular interest is the use of sterically hindered nucleophiles to surmount the unfavorable stereochemical outcome, leading to acetate aldol adducts, in nucleophilic addition to the aldehyde derived from propionates. The approach is based on the addition of an enoxysilane (bearing a removable phenylselenide
Further studies on chromium(II)-mediated homoallylic alcohol syntheses
作者:Michael D. Lewis、Yoshito Kishi
DOI:10.1016/s0040-4039(00)87337-2
日期:1982.1
The stereochemical outcome of chromium(II)-mediated syntheses of homoallylic alcohols has been examined on 11 aldehydes, – .
铬(II)高烯丙醇的合成介导的立体化学结果已经检查了11种醛,- 。
Diastereoselective Mukaiyama and Free Radical Processes for the Synthesis of Polypropionate Units
作者:Yvan Guindon、Jean-François Brazeau
DOI:10.1021/ol049086h
日期:2004.7.1
Reported herein is the synthesis of 8 out of 16 polypropionates derived from our propionate units. A new strategy involving a stereoselective Mukaiyama aldol reaction followed by a stereoselective free-radical-based hydrogen transfer, both under Lewis acid control, is used. Of particular interest is the remarkable reactivity of (i-PrO)TiCl3 in this context to give only the 3,4-anti bromoesters.