98891-63-5Relevant academic research and scientific papers
185-nm Photochemistry in the Synthesis of Enantiomerically Pure Pyrethroids and of Analogues
Frauenrath, Herbert,Philipps, Thomas
, p. 1303 - 1310 (2007/10/02)
Enantiomerically pure methyl (1R)-trans-3-formyl-2,2-dimethyl-1-cyclopropanecarboxylate (R-5b) and its (1R)-cis-analogue (R-6b) are prepared in a few steps from easily accessible rac-tetrahydro-2,2-dimethyl-3-furancarbaldehyde (rac-1).Key steps in this sequence are the optical resolution of carboxylic acid rac-2a in an early stage of the sequence and the dihydrofuran-cyclopropanecarbaldehyde rearrangement with 185-nm light.The cis-trans-isomers rac-5e and rac-6e are also prepared by the same procedure.In the presence of morpholine R-6b is epimerized to yield R-5b in nearly quantitative yield.
