New methodology for the [4+3] cycloaddition reactions: generation of oxyallyl cations from α,α′-diiodoketones under sonochemical or thermal conditions
2001; Elsevier BV; Volume: 42; Issue: 44 Linguagem: Inglês
10.1016/s0040-4039(01)01671-9
ISSN1873-3581
AutoresÁngel M. Montaña, Pedro M. Grima,
Tópico(s)Organic Chemistry Cycloaddition Reactions
ResumoA new methodology to perform [4+3] cycloaddition reactions of suitable dienes and 1,3-dimethyl-2-oxyallyl cations is presented. The reaction is carried out starting from commercially available dienes and easy-handling α,α′-diiodoketones, which are reduced by the Zn/Cu couple to generate the oxyallyl cation as intermediate. The reaction is carried out under mild thermal or sonochemical conditions at low temperatures (from 0 to −44°C) and for short reaction times (<15 min). This methodology represents a good alternative respect to the actual procedures based on other reducing agents or starting from more elaborate precursors of the oxyallyl cations.
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