Die Einführung der Schutzgruppe (I) in 25 verschiedene Aminosäuren verläuft größtenteils in ausgezeichneten Ausbeuten.

No abstract

A synthesis of racemic thalidomide (1) was described and the important formal [3+3] cycloaddition strategy was a keystep. The total yield of thalidomide (1) was 18% in five steps from known 3.

A formal synthesis of (±)‐isodihydronepetalactone (1) from cyclobutenone 5 was de scribed. Baeyer‐Villiger lactonization of cyclobutanone 8 followed by decholorination led to lactone 4, which under went a series of functional group trans formations, furnished cyclopentanone derivative 15. Shapiro reaction on hydrazone derivative in the presence of excess dry ice gave lactone 2. Lactone 2 had previously been converted to isodihydronepetalactone (1).

Procedures for preparing C‐terminal free peptides from hydrolysis of its corresponding methyl or benzyl esters catalyzed by alkaline protease has been developed. N‐protected peptides having side‐chain ester protecting groups or successive hydrophobic amino acid residues in its sequence are hydrolyzed selectively at C‐terminal only and leave other bonds (β and γ‐ ester or peptide bonds) intact. Compounds which cause a side reaction in base mediated saponification could be hydrolyzed safely by this procedure. Products of this hydrolysis are useful intermediates for fragments coupling in the solid phase peptide synthesis.