Fused azetidine derivatives

The fused azetidine derivative of bactobolin 477 has been prepared <1998JAN184>. The azatricycle 186 has been synthesized by an intramolecular nucleophilic cyclization (see Section 2.04.7.1) <20020L1259>. 

The primary mode of electrophilic attack on the azetidine of fused-ring derivatives is acid-catalyzed opening of the bridging bond. For example, l-azabicyclo[2.2.0]hexane (4) gives 4-chloropiperidine (21) on treatment with hydrogen chloride (64HCA2145). 

A derivative 229 of decahydroacridine is obtained when morpholinocyclohexene is treated with benzylideneaniline in acetic acid. The authors propose that the reaction proceeds via the formation and cleavage of a series of fused azetidines (Scheme 8)119. 

Examples of the synthesis of fused-ring azetidines by ring closure onto a preformed azetidine are uncommon, in contrast to approaches used for the preparation of fused ring azetidinones (see Sections 5.12.3, 5.11.4.4 and 5.10.4.3). The l,3-diazabicyclo[3.2.0]hep-tane derivative (48) was prepared (72JOC516) by cyclization with DCC of the carbamoyl-azetidine followed by thermal rearrangement of the intermediate thiazolidinone (Scheme 6). 

Many interesting compounds can be prepared by the Diels-Alder reaction, some of which would be hard to make in any other way. AzeUnes react with dienes to form cyclohexene derivatives fused to a four-membered ring amine (azetidine). ... 

A dithiazole ring fused to an azetidine is formed by treating the thioacyl derivative with A -chlorosuccinimide and a tertiary amine. The cis irons isomer ratio varies with temperature. 

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