Shucai Liang

Microbial transformation of androst-4-ene-3,17-dione by Beauveria bassiana.

The microbial transformation of androst-4-ene-3,17-dione (I) by the fungus Beauveria bassiana CCTCC AF206001 has been investigated using pH 6.0 and 7.0 media. Two hydroxylated metabolites were obtained with the pH 6.0 medium. The major product was 11alpha-hydroxyandrost-4-ene-3,17-dione (II) whereas the minor product was 6beta,11alpha-dihydroxyandrost-4-ene-3,17-dione (III). On the other hand, four hydroxylated and/or reduced metabolites were obtained with the pH 7.0 medium. The major product was 11alpha,17beta-dihydroxyandrost-ene-3-one (V) and the minor products were 17beta-hydroxyandrost-ene-3-one (IV), 6beta,11alpha,17beta-trihydroxyandrost-ene-3-one (VI) and 3alpha,11alpha,17beta-trihydroxy-5alpha-androstane (VII). The products were purified by chromatographic methods, and were identified on the basis of spectroscopic methods. This fungus strain is clearly an efficient biocatalyst for 11alpha-hydroxylation and reduction of the 17-carbonyl group.

Concise synthesis of the angular dihydrofuroquinoline alkaloids via cyclopropane opening in the presence of polyphosphoric acid

Abstract We report a concise method for synthesis of dihydrofuroquinolinone alkaloids, in which the cyclopropane opening and closure was the key step. The only angluar type product was obtained in fairly high yields. IR, UV, 1H NMR, 13C NMR, and MS were used to confirm the structure. A possible mechanism in also described.

Facile way to synthesize Nα-boc-Nβ-Cbz-2,3-diaminopropionic acid derivatives via 5-oxazolidinone

Abstract An economical and facile synthesis of Nα‐Boc‐Nβ‐Cbz‐2,3‐diaminopropionic acid derivatives is reported. The key aspect of this method is employment of N‐Boc‐5‐oxazolidinone moiety to simultaneously provide proper protection of α‐amido and α‐carboxyl functional groups and affords the desired isocyanate 5 successfully by a Curtius rearrangement. The obtained intermediate 6 can be readily converted to various derivatives of Nα‐Boc‐Nβ‐Cbz‐2,3‐diaminopropionic acid by conventional procedure.