A microbially-based approach for the synthesis of chiral secondary alcohols bearing the difluoromethyl or chlorodifluoromethyl group
摘要:
A synthetic approach to both enantiomers of the secondary alcohols [Ph(CH2)n CH(OH)CXF2 (n = 0-2) C6H13(CH2)n CH(OH)CFX2 (n = 0 or 2) and CXF2CH(OH)CH2CO2Et [X = H or Cl], involving the stereoselective hydrolysis of ester derivatives, is described. The absolute configurations of these difluoromethylated or chlorodifluoromethylated molecules were determined.
DOI:
10.1016/s0022-1139(00)81174-4
作为产物:
描述:
二氟氯乙酸 、 alkaline earth salt of/the/ methylsulfuric acid 以80%的产率得到1-chloro-1,1-difluoro-3-phenyl-2-propanone
Zinc-copper(I) chloride or -silver(I) acetate promoted aldol reaction of chlorodifluoromethyl ketones with carbonyl compounds. A general and effective route to α,α-difuluoro-β-hydroxy ketones
作者:Manabu Kuroboshi、Takashi Ishihara
DOI:10.1016/s0040-4039(00)96894-1
日期:1987.1
Chlorodifluoromethyl ketones efficiently underwent the aldol reaction with a variety of aldehydes or ketones in the presence of zinc, a catalytic amount of copper(I) chloride or silver(I) acetate and molecular sieves to give the corresponding α,α-difluoro-β-hydroxy ketones in good to excellent yields.
This invention relates to alkylamino and alkyl amino alkyl diarylketones of the formula ##STR1## where Ar is aryl of the formula ##STR2## where V is hydrogen, halogen, loweralkyl, loweralkoxy, CF.sub.3, No.sub.2 and u is an integer of 1 to 3; X and Y are independently CH.sub.2 --, --CH.sub.2 -- or --CHF--; Z and W are independently --CH.sub.2 --, --O--, --CHOH--, or --CHF--; m, n, p, q and t are integers which are independently 0 or 1; R.sub.1 is H or loweralkyl; R.sub.2 and R.sub.3 are loweralkyl; and the pharmaceutically acceptable acid addition salts thereof and where applicable the geometric and optical isomers and racemic mixtures thereof. The compounds of this invention display utility as analgesic agents and as agents for alleviating various memory dysfunctions, characterized by a decreased cholinergic function, such as Alzheimer's disease.
A convenient synthesis of 2,2-difluoro enol silyl ethers from chlorodifluoromethyl ketones
作者:Masayuki Yamana、Takashi Ishihara、Teiichi Ando
DOI:10.1016/s0040-4039(00)81449-5
日期:——
Various chlorodifluoromethyl ketones can be converted to the corresponding 2,2-difluoro enol silylethers in good yields, by the action of zinc dust and chlorotrimethylsilane in dry acetonitrile at 60°C.
NEW LOW-VALENT TITANIUM CATALYZED REACTION OF CHLORODIFLUOROMETHYL KETONES LEADING TO α,α-DIFLUORINATED β-HYDROXY KETONES
作者:Takashi Ishihara、Tohru Yamanaka、Teiichi Ando
DOI:10.1246/cl.1984.1165
日期:1984.7.5
Various chlorodifluoromethyl ketones underwent the aldol-type reaction with aldehydes or ketones by the action of titaniumtetrachloride and zinc reagent in tetrahydrofuran at room temperature to give moderate to good yields of α,α-difluorinated β-hydroxy ketones.
Facile syntheses of gem-difluoroalkenes from chlorodifluoromethylketones
作者:Jean-Pierre Bégué、Danièle Bonnet-Delpon、Jonathan M. Percy、Michael H. Rock、Robin D. Wilkes
DOI:10.1039/c39950001857
日期:——
Chlorodifluoromethyl ketones reacted with diazomethane to afford epoxides in high yield; upon treatment with butyllithium, the epoxides underwent efficient ring opening to afford 3,3-difluoro-2-alkyl-alken-1-ols, suitable substrates for sigmatropic rearrangement leading to compounds containing a CF2 group in mid-chain.