Ring Contraction of 1,2-Di-hydronaphthalenes with Iodine(III) and its Application in Total Synthesis of (±)-Indatraline

Author(s)

Fernanda Amaral de Siqueira

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2008-04-18

Examining board members

Luiz Fernando da Silva Junior; Carlos Roque Duarte Correia; Massuo Jorge Kato; Vera Lúcia Pardini; Marcus Mandolesi Sá

• Advisor: Luiz Fernando da Silva Junior

Abstract

This thesis presents the total synthesis of (±)-indatraline, representing a synthetic application of the ring contraction reaction of 1,2-dihydronaphthalenes mediated by iodine(III). The target molecule is a 3-phenyl-1-indanamine, which is a candidate for the treatment of cocaine abuse. In the proposed route, we chose a 4-phenyl-1-tetralone as a starting material, which was converted into the corresponding 1,2-dihydronaphthalene. The key step was a ring contraction of 1-(3,4-dichlorophenyl)-1,2-dihydronaphthalene, promoted by hydroxyl(tosiloxy)iodobenzene (HTIB), which furnished the trans indan in moderate yield and high diastereoselectivity. The synthetic sequence was concluded in 10 steps. We also described studies toward the oxidation of a series of 1,2-dihydronaphthalenes mediated by iodine(III), aiming the synthesis of indans through a ring contraction reaction. The reactions of disubstituted dihydronaphthalenes was performed in MeOH. The substrates containing a metoxy group at the aromatic ring led to desired indans in poor yields. The 6,8- dimethyl-1,2-dihydronaphthalene was the substrate that gave the ring contraction product in higher yield. The reactions of trisubstituted olefins with iodine(III) was performed in CH3CN, furnishing indans in moderated yields. The presence of the phenyl group at the olefin led to another product of rearrangement. These results allowed to evaluate the influences of the ring size and of the substituents at the rearrangement. The presence of a methyl group at the 4- position contributed for the formation of indan (AU)