203253-68-3Relevant academic research and scientific papers
Asymmetric induction in Darzens condensation by means of (-)-8-phenylmenthyl and (-)-menthyl auxiliaries
Takagi, Ryukichi,Kimura, Jyunji,Shinohara, Yoshihiro,Ohba, Yuko,Takezono, Kyoko,Hiraga, Yoshikazu,Kojima, Satoshi,Ohkata, Katsuo
, p. 689 - 698 (1998)
Asymmetric Darzens condensation of benzaldehyde and various ketones has been investigated. The condensation of acetophenone, propiophenone and symmetric ketones with (-)-8-phenylmenthyl halogenoacetates 3a,b afforded the corresponding glycidic esters cis-12, cis-13 and 15-19 in 77-96% de, respectively, as the major products. Aza-Darzens condensation between N-benzylideneaniline and 3a occurred to give the trans-aziridine 21 as the major isomer in >85% de. The stereochemistry of the major diastereoisomers of cis-12 and 18 was confirmed by their conversion into the known optically active diols 22 and 24. The configuration of the major product of cis-12 was determined to be 2R,3R and that of 18 to be 2R. The geometric and disastereofacial selectivities were understandable in terms of the open-chain or non-chelated antiperiplanar transition state model in the initial aldol-type reaction.
Influence of the chiral auxiliary on the stereoselectivity of the S(RN)1 C-alkylation of 2-nitropropionate anions
Nouguier, Robert,Beraud, Valerie,Vanelle, Patrice,Crozet, Michel P.
, p. 5013 - 5014 (2007/10/03)
A series of carbohydrate-derived 2-nitropropionate anions was reacted with p-nitrobenzyl chloride under S(RN)1 reactions conditions, the diastereomeric ratios were moderate, but increased when the carbohydrate moiety was replaced by the more bulky 8-phenylmenthol.
