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1999amide formation, amide hydrolysis amide formation, amide hydrolysis O 0320 -065One-Pot Neat Reactions of Carboxylic Esters and Alkylenediamines for Efficient Preparation of N-Acylalkylenediamines. -A convenient and efficient monoamidation, even for the preparation of tertiary amides, by reaction of esters (I) and (V) with diamines (II) and (VI) is described. The resulting amides are useful building blocks for the synthesis of antihypertensive agents.

1993 stereochemistry stereochemistry (general, optical resolution) O 0030 -060"Non-Evans" syn-Aldol via Aldolization of Chlorotitanium Enolate with TiCl4/Aldehyde Complex.-The chiral fused Npropanoyloxazolidinone (IIa) and the corresponding thione (IIb), prepared from ketopinic acid (I), are converted to their titanium enolates and then treated with the TiCl4 complexes of the aldehydes (VIII) to produce the aldol adducts (XIII) -(XV) or (IX) and (X). The diastereomers (X) are almost exclusively obtained from the thione (IIb) and the aldehydes (VIII). They are hydrolyzed and esterified to give the chiral ss-hydroxy carboxylates (XII) under recovery of the chiral auxiliary (VI), the direct precursor of (IIb). The coupling of the oxazolidone (IIa) with the aldehydes (VIII) in the presence of TiCl4 proceeds with significantly lower diastereoselectivity.-(YAN, T.-H.; LEE, H.-C.; TAN, C.

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