Peri-Heterocycles with Four-Membered Heteroring

Peri-Heterocycles with Four-Membered Heteroring 

Naphthalene derivatives in which positions 1 and 8 are linked by one heteroatom are the simplest representatives of the peri-annelated heterocyclic systems. Compounds in this group are interesting because of possi- 

The first information about the synthesis of naptho[bc]-oxete 11 (33BRP394511) was incorrect (70JOC4261). Oxidation of a-naphthol by ferric chloride or the attempted dehydration of 1,8-dihydroxynaphthalene 10 led to complex mixtures where the desired compound 11 was not detected (70JOC4261). 

Unlike naphtho[6c]oxete, described previously, its thio analog 20 is a stable compound which can be obtained in high yield (97-100%) on photolysis of naphtho[c /]thiol 5,5-dioxide 18 (76JA6643) or naphtho[ / ]-thiadiazine 19 (79JA7684). Naphtho[bc]thiete 20 is also formed in low 

An equimolar ratio of a substrate and oxidizing agent gives oxides 23 and 24 in yields of 71% and 4%, respectively, whereas triple the amount of oxidizing agent leads only to dioxide 24 in 93% yield. The intermediate naphtho[ fe]thiadiazine 5-oxide 22 is unstable, and it is decomposed with nitrogen elimination even at room temperature. Dioxide 24 may be obtained only on oxidation of monoxide 23, and not via the formation of 

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A. Peri-Heterocycles with Four-Membered Heteroring... 

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