Morpholinone derivative

An alternative multistep approach to the synthesis of a-amino acids, using the boronic acid as the precursor of the carboxylic acid group, was reported by Harwood et al. [56]. Thus, reaction of a chiral morpholinone derivative with furyl boronic acid and various aldehydes gave, in a diastereocontrolled manner, the corresponding adducts which were converted in several steps to the a-amino acids [56],... 

A ring enlargement process was used effectively to access the enantiopure pyrrolo [ 1,4]oxazepine-9a(7//)-carboxylate derivatives 142 and 143. The sequence involved copper (Il)-catalysed decomposition of an a-diazocarbonyl derivative attached to a chiral morpholinone, and a carbenoid, spiro-[5,6]-ammonium ylide, Stevens [1,2] rearrangement sequence. The Stevens and related rearrangements have considerable further potential for novel heterocyclic syntheses <00TA3449>. 

Morpholinone 177, derived from allyl glycine, cyclized stereoselectively under UV irradiation (A > 342 nm) in the presence of 9,10-anthracene dicarbonitrile (ADC) and biphenyl (PB) to give compound 176 as a single diastereo-isomer <2001JOC6896> (Scheme 26). 

The thermodynamically controlled reactions between ClCH2GeMe2Cl and O- or N-TMS derivatives of 5-ethyl-3-morpholinone and 2,5-piperazinedione yield the monochelate 147 and bis-chelate 148a, respectively. 

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