Claisen rearrangement boron trifluoride etherate

Allyloxy-l,2,3,6-tetrahydropyridine 241 undergoes Claisen rearrangement in cymene to give 4-allyl-3-oxo-piper-idine 242. The boron trifluoride etherate-mediated Claisen rearrangement gives only the 2-allyl isomer 244 due to the initial isomerization of tetrahydropyridine 241 into 1,2,3,4-tetrahydropyridine 243 by the Lewis acid (Scheme 61) <1999S1814>. 

The reaction of linalool with boron trifluoride etherate has been re-examined no pinenes or camphene were obtained.146 Dehydrolinalool reacts with methyl iso-propenyl ether under acidic conditions by Claisen rearrangement to give the allene (58).147 Further papers in this section include reaction of monoterpenoid alcohols with paraformaldehyde-acetic anhydride-sodium acetate,148 rearrangement of the alcohol (47 X = OH) to the oxabicycloheptane (59) and the ketone (60),149 and the rearrangement of a typical monoterpenoid vicinal hydroxy-ester to an epoxide.150... 

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