147274-53-1Relevant academic research and scientific papers
Enzymatic resolution of racemic secondary cyclic allylic alcohols
Winska, Katarzyna,Grudniewska, Aleksandra,Chojnacka, Anna,Bialonska, Agata,Wawrzenczyk, Czeslaw
experimental part, p. 670 - 678 (2010/08/07)
The resolutions of five racemic cyclic alcohols: 6,6-dimethylcyclohex-2-en-1-ol (±)-5, 4,4-dimethylcyclohex-2-en-1-ol (±)-7, 5,5-dimethylcyclohex-2-en-1-ol (±)-11 and isomeric trans-(±)-13 and cis-piperitols (±)-14 are presented. They were resolved by enzymatic esterification with vinyl esters or by enzymatic hydrolysis of their racemic esters in phosphate buffer. The following lipases were used as biocatalysts: Novozyme 435 (Candida antarctica), Amano PS (Burkholderia cepacia) and lipase from Candida cylindracea. All isomers of alcohols were obtained with at least 96% ee.
Ozonolyses of 4,4-dimethyl-2-cyclohexen-1-yl acetate and 4,4-dimethyl-2-cyclopenten-1-yl acetate. Competition between the steric effects of the allylic methyl groups and the electronic effects of the acetoxy group on the direction of cleavage of the primary ozonides
Kawamura, Shin-Ichi,Yamakoshi, Hideyuki,Nojima, Masatomo
, p. 5953 - 5958 (2007/10/03)
In order to understand the relative directing effects of the substituent steric and electronic effects on the cleavage of the primary ozonides, ozonolyses of a series of cyclohexene and cyclopentene derivatives were conducted in methanol or in ether in the presence of trifluoroacetophenone. The ozonolysis of 4,4-dimethyl-2-cyclohexen-1-yl acetate (1k) in methanol provided exclusively the α-methoxyalkyl hydroperoxide 7k derived from capture of 5-acetoxy-5-formyl-2,2-dimethylpentanal oxide by the solvent, while in the case of the relevant 4,4-dimethyl-2-cyclopenten-1-yl acetate (11) the solvent-captured product 61 derived from trapping of 2-acetoxy-5-formyl-5-methylpentanal oxide was the major product. The remarkable difference in the regiochemistry of the fragmentation between the primary ozonides, 2k and 2l, is rationalized in terms of the significant difference in the steric congestion.
