Synthesis 2004(7): 1115-1118  
DOI: 10.1055/s-2004-815971
PSP
© Georg Thieme Verlag Stuttgart · New York

Reductive Ring Opening of Oxygen-Containing Benzo-Fused Heterocycles by an Arene-Catalysed Lithiation

Miguel Yus*, Benjamín Moreno, Francisco Foubelo
Departamento de Química Orgánica, Facultad de Ciencias and Instituto de Síntesis Orgánica (ISO), Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
Fax: +34(965)903549; e-Mail: yus@ua.es;
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Publikationsverlauf

Received 29 December 2003
Publikationsdatum:
12. Februar 2004 (online)

Abstract

The reductive ring opening of phthalan and isochroman in a 8 mmol scale process, using a small excess of lithium (1.35 equiv) and a substoichiometric amount of DTBB (3 mol%), leads to functionalised organolithium compounds, which after reaction with (-)-menthone as electrophile followed by hydrolysis with water, gives the corresponding diols in good yields with high stereoselectivity. Dehydration of these diols leads to the corresponding oxygen-containing heterocycles, which are homologous of the starting heterocycles.