Reactions with arynes

Benzo[b]furan-4(5H)-one, 6,7-dihydro-synthesis, 4, 710 Benzofuranones H NMR, 4, 579 Benzo[b]furanones from 3-hydroxyflavanone, 3, 729 Benzo[b]furan-2(3H)-ones — see 2-Coumaranones Benzo[b]furan-3(2H)-ones IR spectra, 4, 590 reactions, 4, 650 Benzo[ c]furan-1 (3 W) -ones carbanions, 4, 579 H NMR, 4, 579 reactions with arynes, 1, 415 structure, 4, 552... 

The reaction of benzyne with cyclohexadiene has been known for some time 4>, but although a number of steroidal cis-dienes are readily available no reactions with arynes had been reported prior to our beginning such investigations 145>. This was somewhat surprising in view of the number of reports concerning the modification of steroids by means of reactions with carbenes 146 i49) and the known Diels-Alder reactions of steroidal dienes and trienes iso.isi). 

Cyclizations by formation of carbon—selenium bonds represent a modern method with a high synthetic potential in the chemistry of cyclophanes. Selenocyanates such as 16 are accessible usually in excellent yields through the reaction of bromides with KSeCN [27], The reaction with benzylic bromides under reductive conditions using the dilution principle results in good to excellent yields of [3.3]di-selenacyclophanes which can be deselenized photochemically, pyrolytically (without previous oxidation), or by reaction with arynes, Stevens rearrangement and subsequent reaction with Raney nickel. [2.2]Metacyclophane (18), for example, is accessible in 47% total yield by using this sequence of reactions starting with... 

Other methods of arylation include reaction with arynes , p-benzoquin-... 

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