Electrophilic Addition of Allylic Carbocations to 2-Cyclopropylidene-2-arylethanols: A Strategy to 3-Oxabicyclo[3.2.0]heptanes
作者:Bo Meng、Xian Huang、Luling Wu
DOI:10.1002/adsc.201201073
日期:2013.9.16
We have developed an electrophilicaddition of allyliccarbocations to 2‐cyclopropylidene‐2‐arylethanols constructing carbon‐carbon bonds with excellent regio‐ and stereoselectivities. The reaction affords 3‐oxabicyclo[3.2.0]heptanes in moderate to good yields via the electrophilicaddition/ring‐opening/vinyl group shift/intramolecular cyclization sequence.
Process for preparing optically active secondary alcohols having nitrogenous or oxygenic functional groups
申请人:——
公开号:US20030045727A1
公开(公告)日:2003-03-06
A process for preparing optically active secondary alcohols of the general formula (3), [wherein R
1
is linear lower alkyl, an aromatic ring group, or the like; A is CH
2
NR
2
R
3
or the like; n is an integer of 0 to 2; and * represents an asymmetric carbon atom] by asymmetrically hydrogenating a ketone compound of the general formula (1) having nitrogenous or oxygen functional group at any of the a-, &bgr;- and &ggr;-positions, with selectivity among functional groups by the use of a ruthenium/optically active bidentate phosphine/diamine complex as the catalyst in the presence of hydrogen alone or together with a base. The optically active secondary alcohols obtained by the process are useful as drugs and intermediates for the preparation of drugs.
A practical entry to β-aryl-β-alkyl amino alcohols: application to the synthesis of a potent BACE1 inhibitor
作者:Oscar Delgado、Antonio Monteagudo、Michiel Van Gool、Andrés A. Trabanco、Santos Fustero
DOI:10.1039/c2ob25845e
日期:——
The 1,2-addition of alkyl Grignard reagents to readily available N-tert-butanesulfinyl ketimines, bearing an α-silyloxy substituent, proceeds in high yields and excellent diastereocontrol. The utility of the present method was demonstrated by the synthesis, in enantiomerically pure form, of one recently disclosed β-secretase (BACE1) inhibitor.
A straightforward and efficient diastereoselectivesynthesis of (S)- and (R)-α-phenylserine is reported. The key step involves an asymmetric Strecker reaction of a chiral N-sulfinyl ketimine, which was obtained from the commercially available 2-hydroxyacetophenone.