Naming Stereogenic Centers in Strychnine

A structural formula of the the alkaloid strychnine is drawn below. The seven chiral centers are labled by magenta numbers.
A 3-D model of this compound is shown to its right. In this display the molecule can be moved about by using the mouse.
The chiral centers of the model may be labeled in the manner of the drawing by clicking the designated button.
You should provide a C.I.P. configuration for each chiral center by selecting an R or S notation following its number.
The configuration of N19 is locked by the bridged rings. Here the non-bonding electron pair is the lowest priority substituent.


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Stereogenic Centers in Morphine
Stereogenic Centers in Taxol

Identify the configuration at each center
Carbon # R S

19 N