The preparation of vicinal difluoroolefinic carbonyl compounds and their application to the synthesis of difluororetinal analogs
作者:A.E Asato、R.S.H Liu
DOI:10.1016/s0040-4039(00)84789-9
日期:1986.1
The preparation of a novel vicinal difluorinated retinal analog is described. The key difluoroolefinic intermediate in the synthesis was prepared by the reaction of DAST with ethyl acetoacetate.
NOVEL SULFONE DERIVATIVES AND PROCESS FOR PRODUCING THESE
申请人:SUMITOMO CHEMICAL COMPANY LIMITED
公开号:EP1359143A1
公开(公告)日:2003-11-05
There are provided production processes for cyclic sulfone compounds of formula (2) or (4):
or
wherein the dashed lines represent that a double bond is present at one of three positions indicated; Ar and the wavy line are as defined below, characterized in that compounds of formula (1) or (3):
or
wherein Ar is aryl optionally having a substituent(s) and the wavy line represents either one of E/Z geometrical isomers or their mixture, is subjected to cyclization in the presence of an acid catalyst. These processes are excellent processes as the production processes for retinol from the viewpoints of raw material costs, intermediate purification, the number of steps, and the like.