A new entry into pyrroloiminoquinone marine alkaloids, makaluvamines, has been developed. The key 1,3,4,5-tetrahydropyrrolo [4,3,2-de]quinoline intermediates 11 and 18 were prepared by aryne-mediated cyclization of the 4-chloro-6-methoxytryptamine derivatives 10 and 17, respectively. The requisite substituents at the indole 4- and 3-positions of 10 and 17 were efficiently assembled by sequential use of directed lithiation of 1-triisopropylsilyl-6-methoxygramine (6) and fluoride ion-induced elimination-addition of the methiodide of 4-chloro-1-triisopropylsilyl-6-methoxygramine (7) as key reactions. (C) 1998 Elsevier Science Ltd. All rights reserved.