Formation of the S, S, S epimer is also avoided by keeping reaction temperature below-15 �C.
12.
Thus either epimer is converted into a near 1 : 1 mixture of both isomers upon full conversion of the substrate.
13.
Under mild basic conditions, this stereogenic center isomerizes; the S epimer is called "'neoamygdalin " '.
14.
This epimer was then converted to the "'35 "'by the simultaneous action of methanol and thiophenol.
15.
Mthanolysis of lactone 10 with NaOMe forms a mixture of hydroxyl ester 11 and its C-4a epimer ( Pancratistatin numbering ).
16.
While at Brown University, De Groot worked with Gabriel Meister and Bill Jesdale to develop the EpiMer and EpiMatrix epitope mapping tools.
17.
However, this possibility was excluded by the synthesis of the 11 epimer and the demonstration that it has different chromatographic behavior from ouabain.
18.
However, the undesired isomer can be recycled to the desired epimer in three steps, including Swern oxidation and Corey s asymmetric reduction.
19.
It is the ? epimer of zeranol ( ?-zearalanol ) and is a major metabolite of zeranol but with less biological activity.
20.
The alpha compound was therefore converted its epimer "'34 "'by first equilibrating in excess base followed by reacidifiying and diazomethane treatment.
