Stereochemistry and Regiochemistry of Electron Impact Thermally and Photolytically Induced Eliminations from 2-Decalyl Acetates

Article abstract of DOI:10.1021/jo01289a024

Deuterium-labeled compounds are used to define the stereochemistry and regiochemistry of the electron impact induced elimination of acetic acid from trans,trans-2-decalyl acetate and trans,cis-2-decalyl acetate.Both compounds fragment with very predominant abstraction of equatorial hydrogen atoms.Since the trans equatorial hydrogens of the trans,trans acetate cannot be approached within the requisite 1.8 Angstroem by the acetate carbonyl in any boatlike conformer, this result demonstrates that hydrogen abstraction largely occurs from the chair conformer of the cyclohexyl ring.Both compounds fragment with predominant elimination toward C-1 rather than C-3.The regiochemistry of the pyrolysis of the acetates and the photolysis of the corresponding phenylacetates is compared with that of the mass spectral elimination.