An Amino Alcohol Ligand for Highly Enantioselective Addition of Organozinc Reagents to Aldehydes: Serendipity Rules
作者:William A. Nugent
DOI:10.1021/ol0259488
日期:2002.6.1
bis(2-bromoethyl) ether. Subsequent hydrogenation over 5% Rh on alumina in the presence of morpholine unexpectedly stops at the hexahydro derivative 4. Amino alcohol 4 promotes the enantioselectiveaddition of diethylzinc to aldehydes at room temperature in up to 99% enantiomeric excess.
Enantioselective Synthesis of Allylic Alcohols via an Oxazaborolidinium Ion Catalyzed Diels−Alder/Retro-Diels−Alder Sequence
作者:Simon Jones、Damien Valette
DOI:10.1021/ol902280d
日期:2009.11.19
A triflimide-activated oxazaborolidine catalyst successfully promoted the asymmetric Diels−Alder reaction of 9-methylanthracene with methacrolein in high regio- and enantioselectivity. The cycloadduct obtained was subsequently used as a chiral template to access secondary and tertiary allylic alcohols in good to high enantiomeric excess via a cycloreversion by flash vacuum pyrolysis.
A short and convergent synthesis of jerangolid D is described. As key steps, a Blaise reaction is employed to construct the lactone ring, a diastereoselective multicomponent Sakurai condensation leads to the dihydropyran ring, and the skipped diene is assembled using a modifiedJuliaolefination.
描述了 jerangolid D 的短而收敛的合成。作为关键步骤,使用 Blaise 反应构建内酯环,非对映选择性多组分 Sakurai 缩合导致二氢吡喃环,并使用改进的 Julia 烯化组装跳过的二烯。
Formal Total Synthesis of (+)-Methynolide
作者:Janine Cossy、David Bauer、Véronique Bellosta
DOI:10.1055/s-2002-25364
日期:——
A convergent total synthesis of (+)-methynolide was achieved in 23 steps highlighted by a ring-closing metathesis, a Takai reaction, a Sharpless kinetic resolution of an allylic alcohol and a crotylboration.
Studies in polypropionate synthesis: stereoselective synthesis of (−)-denticulatins A and B
作者:Ian Paterson、Michael V. Perkins
DOI:10.1016/s0040-4039(00)77719-7
日期:1992.2
from the ethyl ketone (R)-8. Key steps are the novel boron-mediated aldol/reduction, 8 → 12, the titanium aldol couping, 6 + 5 → 18, and the HF-pyridine cyclisation, 20 → 2. Epimerisation at C10 in 20 led to ()-denticulatin A (1).