The glycosidic fraction isolated from the seeds of Styrax officinalis L. yielded on acid hydrolysis egonol and a new benzofuran derivative which was formulated as 2-(3.4-dimethoxyphenyl) -5-(3-hydroxypropyl)-7-methoxybenzofuran. EGONOL was isolated by Okadal as an unsaponifiable constituent of the semen-oil of Styrax japonicum Sieb et Zucc; and Kawai et aL2 elucidated its structure and formulated it as 5-(3-hydroxypropyl)-7-methoxy-2-(3,4methylenedioxyphenyl) benzofuran (I).The glycosidic fraction of the seeds of Styrax oficinalis L. yielded after acid hydrolysis and chromatography egonol (I) and two other minor constituents. We describe here the structure elucidation of one of the crystalline minor constituents, for which we propose the formula 2-(3,4-dimethoxyphenyl)-5-(3-hydroxypropyl)-7-methoxybenzofuran (11).The empirical formula C,,H,,05 indicated for compound (11) by analysis was supported by mass spectro-

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Some dipeptides of threo-P-hydroxyaspartic acid were synthesised, by use of a-benzyl N-benzyloxycarbonyl-threo-P-hydroxyaspartate, with carbodi-imides as condensing agents.Jerusalem, Israel THE synthesis of peptides containing amino-acids with an alcoholic hydroxy-group , such as serine or threonine , presents certain difficulties due to the reactivity of the hydroxy-group, the lability of the peptide bonds (in the case of serine l), and the tendency for p-elimination reactions and N-0 (or 0-N) acyl shifts.2 Further complications are encountered in the synthesis of peptides containing the p-hydroxyaspartic acids ; these possess an additional carboxy-group which makes them tetrafunctional. Only the erythro-form of phydroxyaspartic acid has been isolated from natural sources,3 but both the threo-and erythro-isomers, first synthesized by Dakin,4 can now be prepared stereospecifically. 6 We have attempted to synthesise dipeptides containing the threo-isomer, with a view to preparing the p-hydroxy-L-aspartyl analogue of the physiologically active oligopeptide angiotensin I1 , an octapeptide with L-aspartic acid at its N-terminal end. We first used the more readily available racemic form to test the methods and then the L-isomer, obtained by resolution of N-benzyl-threo-p-hydroxy-DL-aspartic acid with L-ephedrine.6The synthesis of peptides containing hydroxy-aminoacids does not necessarily require protection of the hydroxy-group. On the contrary, the use of acyl groups for this purpose increases the possibility of p-elimination. Etherification does not suffer from this disadvantage, but the benzyl ethers cannot be prepared readily from the hydroxy-amino-acids themselves. The hydroxygroup was therefore not protected in this work.One of the classical methods for the production of CCand P-aspartyl peptides is based on the cyclic anhydride obtained when N-benzyloxycarbonylaspartic acid reacts with acetic anhydride.' This procedure , when applied

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