The stereochemical outcome of the 1,3-dipolar cycloaddition reaction t
o alkenes bearing an allylic stereocentre has been studied, with parti
cular attention to the origin of the stereoselectivity. Steric and ste
reoelectronic effects were considered for different 1,3-dipoles. The r
esults find a rationale within the framework of a revised Version of H
ouk's inside alkoxy theory.