MULTICOMPONENT REACTIONS: SYNTHESIS OF SPIROCYCLIC TETRAHYDROPYRAN DERIVATIVES BY PRINS CYCLIZATION.

Substituted spirocyclic tetrahydropyranyl mesylates and tosylates have been synthesized in good yields using a Prins-type cyclization of various cyclic ketones, a homoallylic alcohol and either methanesulfonic or p-toluenesulfonic acid under non-aqueous conditions. The mesylates thus produced could then be transformed into the corresponding Boc-protected amines using an efficient two step procedure.