Allenic esters, process for preparation thereof and process for
申请人:Kuraray Co., Ltd.
公开号:US03978100A1
公开(公告)日:1976-08-31
Allenic esters of the formula: ##EQU1## (specific examples of R, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are given) and a process for the preparation thereof which comprises reacting propargyl alcohol derivatives with 2-substituted ortho-acetic acid esters in the presence of an acidic catalyst. These allenic esters are rearranged in the presence of an alkali catalyst to form .alpha., .beta., .gamma., .delta.-unsaturated carboxylic acid esters and are useful as intermediates in the synthesis of various perfumes, medicines, agricultural chemicals and the like.
Rhodium‐Catalyzed Cyclization of Terminal and Internal Allenols: An Atom Economic and Highly Stereoselective Access Towards Tetrahydropyrans
作者:Johannes P. Schmidt、Bernhard Breit
DOI:10.1002/ange.202009166
日期:2020.12.21
AbstractA comprehensive study of a diastereoselective Rh‐catalyzedcyclization of terminal and internalallenols is reported. The methodology allows the atomeconomic and highly syn‐selective access to synthetically important 2,4‐disubstituted and 2,4,6‐trisubstituted tetrahydropyrans (THP). Furthermore, its utility and versatility are demonstrated by a great functional‐group compatibility and the