Various allyl ethers were converted into the corresponding N-allylcarbamates using chlorosulfonyl isocyanate (CSI) via the stable allylic carbocation rather than β-lactam through [2+ 2] cycloaddition. The reaction of cinnamyl methyl ether with CSI afforded only methyl N-cinnamylcarbamate at 0° C, but at 20° C, it produced a mixture of methyl N- cinnamylcarbamate and methyl N-(1-phenylprop-2-enyl) carbamate in a 2.7: 1 ratio.
