selective protection of the hydroxyl function of 7a-c the resulting siloxy derivatives lla-c were transformed by gold(III) catalysis into pyrroloisoindolones 13a-c in moderate yields. This establishes a new approach to this class of heterocycles in a [3+2] fashion with the alkoxyallenes as functionalized C-3 unit and phthalimide 5 providing the CN moiety. Treatment of primary adducts 7a-c with aqueous sulfuric