If your local dealer insists on cutting your dope with sugar, you should be aware that there is a fix for it now.
Specifically, if the sugar is pure D-ribose and the desired dope is (—)-cocaine, which is the natural stuff indeed, you can convert the former into product with excellent stereoselectivity and an impressive overall yield.
Org. Lett. 2011, 13, 2916-2919. (DOI: 10.1021/ol2009686)
Nah… but seriously, I really enjoyed reading this paper. Apart from the awesome chemistry presented throughout, and do check it out if you like total synthesis, the fact that the authors spend most of page one talking about how bad cocaine is, and then directly proceed to the details of its preparation, made my day.
Scheme 2 is like a text book. Great stuff.