Perspective and Fischer projection

[Chem_Mod]

[b]Question: [/bHow do you convert perspective formulas into Fischer projections? I thought the rule was, no matter what, always have the longest carbon chain on the vertical axis, with C-1 drawn on top of the chain...but in a perspective formula, how can you tell which one is C-1? Also, is there a set place where the dark wedged substituent is supposed to go vs. the light wedged substituent?

[Chem_Mod]

Answer: Don't worry about the atom positions as they can be different for the same molecule. What is important is to have the correct stereochemistry (R or S). Quickest way is to draw a Fischer projection and then determine R or S. If incorrect then change it.