Total synthesis of a protected form of sphingofungin E using the [3,3]-sigmatropic rearrangement of an allylic thiocyanate as the key reaction.
An approach to the stereocontrolled synthesis of the protected form of sphingofungin E (32) starting from the known protected d-glucose derivative 3 is described herein. For the construction of a tetrasubstituted carbon atom that is substituted with nitrogen, the [3,3]-sigmatropic rearrangement of thiocyanate 8 was employed. Subsequent functional group interconversions afforded the highly functionalized fragment, allylic bromide 26. Its coupling reaction with the known C(12) hydrophobic segment 2, followed by further manipulation, completed the total synthesis.
Microbiological reduction of keto-sulfones. Application in a three-step synthesis of (S)-(+)-β-angelica lactone
Abstract Microbiological reductions of several keto-sulfones led to the corresponding hydroxy-sulfones in moderate to high enantiomeric excess. A three-step synthesis of (S)-(+)-β-angelica lactone from ethyl-4-oxo-3-(phenyl-sulfonyl)-pentanoate via the intermediate chiral alcohol is described.
Method validation in pharmaceutical analysis
Method validation in pharmaceutical analysis , Method validation in pharmaceutical analysis , کتابخانه دیجیتال جندی شاپور اهواز