It is possible that the vinylogs of -amino acids of the formula I, according to the principle of vinylogy (1), could prove to be interesting compounds, inter alia, as substrates for certain enzymes.

The Rosenmund-Zetzsche reduction was applied to the optically active Nphthaloyl acyl chlorides (Ia-c) of the naturally occurring amino acids. The crystalline N-phthaloyl derivatives of these aldehydes (Ila-c) were converted into diethyl acetals (IIIa-c) and ethylenemercaptals (Va-c). Hydrazinolysis of the diethyl acetals and the ethylene mercaptals gave the corresponding a-amino aldehyde diethyl acetals (IVa-c) and -amino aldehyde ethylene mercaptals. All of these compounds are optically active. Zagreb, Yugoslavia

Many synthetic methods for the preparation of basic amino acids have been hitherto described (1). In this paper a general method is given for the preparation of basic amino acids from monoamino acids. The starting materials for these syntheses were the N-phthaloyl derivatives of aminoaldehydes obtained from glycine, /3-alanine, and 7-aminobutyric acid.Radde (2) first prepared phthalimidoacetaldehyde (la) from glycine by the Rosemund-Zetzsche reduction of N-phthaloylglycyl chloride. Following the same procedure we obtained in good yields /3-phthalimidopropionaldehyde (lb) from /3-alanine, and 7-phthalimidobutyraldehyde (Ic) from 7-aminobutyric acid.Applying the condensation of aldehydes with 2-mercaptothiaz ol-5-one as Found: C, 35.54; , 3.60.

A new cystine homologue IV showing [α]D −260° has been prepared by applying the Arndt‐Eistert reaction to S‐benzyl‐N‐phthaloyl‐l‐cysteine (I). The high [α]D of this compound supports Fredga's explanation of the high rotatory power of cystine.