H2/Pd-C reductant

Reducing porphycene in the presence of alcoholic sodium metal gives rise to a different reduction product. Under these conditions, it was found, for instance, that the unsubstituted porphycene 3.2 affords the 9,10-dihydroporphycene 3.93 (Scheme 3.1.17) instead of an jV,iV-dihydro- or 2,3-dihydroporphycenes, such as 3.36 and 3.90 (afforded by the H2/Pd-C reduction process discussed above). A species such as 3.93 thus bears a structural analogy to the phlorins of the porphyrin series. Unfortunately, structural information for this class of molecules, including 3.93, is currently lacking. 

The relative and absolute stereochemistry of (+)-trienomycins A (111), B (112) and C (113) were established by chemical degradation studies and the total syntheses of 111 -113 have been reported [173]. Also, the relative and absolute stereochemistry of (+)-mycotrienins I (95) and II (96) were established by chemical correlation with (+)-trienomycin A (111) [173,174]. Both trienomycinol (117), obtained by the reductive hydrolysis of 111 with LiAlH4 at low temperature, and the hydrogenated derivative of 111 derived from H2/Pd-C reduction, lacked cytotoxic activity [175]. 

Methyl 2-acetaraido-2-deoxy-a-D-glucopyranoside was converted to its galacto-lsomer by direct oxidation (Br2 H20) to the 1-keto-deri-vative, isolated by way of the oxime, and reduction (H2 Pd/C) reduction of the oxime led to the 2, il-diamino-2,4-dideoxy-D-galacto-side. ... 

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