Efficient syntheses of four stable-isotope labeled (1R)-menthyl (1S,2S)-(+)-2-phenylcyclopropanecarboxylates.
Many carbenoid cyclopropanation reactions promoted by chiral catalysts give product mixtures reflecting impressive diastereo- and enantioselectivities. Few provide a single chiral product efficiently. This limitation has been overcome in cyclopropanations of styrene and isotopically labeled styrenes with alpha-diazoacetates. Convenient syntheses on a 20 g scale of each of four chiral isotopically labeled (1R)-menthyl (1S,2S)-2-phenylcyclopropanecarboxylates (the 1-d-3-(13)C, 1,(3S)-d2, 1,2,(3S)-d3, and 1,3,3-d3 isotopomers) of better than 99% ee have been realized.
Keliher
Edmund J
EJ
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Box 234, Cambridge, MA 02138, USA.
Burrell
Richard C
RC
Chobanian
Harry R
HR
Conkrite
Karina L
KL
Shukla
Rajesh
R
Baldwin
John E
JE
D002247:Carbon Isotopes; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D020058:Styrene / Q000737:chemistry
D002247:Carbon Isotopes; D002264:Carboxylic Acids; D003521:Cyclopropanes; D020058:Styrene; D003300:Copper; C108892:2-phenylcyclopropanecarboxylic acid