Question

Help!! I need to draw the carbocation intermediate after protonation!

http://tinypic.com/view.php?pic=2qnw903&s=8#.U40xyfldWSo

Answer 1

This looks like an intermediate in terpenoid biosynthesis..hm it's kinda hard to say because all of the alkenes have more or less the same reactivity, so the regioselectivity comes FROM the enzyme. So without further info on the final product (i.e. what the final product is going to be, since there will probably be rearragements) or how/which enzyme you're dealing with, i dont think it's possible to know.