No probably not, but with conditions:
1) if you believed/intended you were receiving 1kg of cocaine even though what you got was 100% sugar, yes your guilty at the very least for conspiracy charges
2) if the sugar had any detectable quantity of cocaine in it, then you received 1kg of cocaine in the eyes of the law
3) if you sold someone 1kg of sugar saying it was cocaine, in the eyes of the law you sold a kg of cocaine even if there was not a single molecule of cocaine involved
In conspiracy charges just trying is guilty, you dont need to succeed with the criminal act. So if for example i call you and im like “bro sell me a kilo of cocaine” and the cops had the phone line tapped they could bust through the door seconds after the call and arrest me for conspiracy to posess cocaine for the purpose of trafficking, even though i never even had the chance to go pickup the cocaine from you. I was conspiring to do it, and that in and of itself is a crime.
But for the sake of prosecution conviction success, they prefer the actual charge over the conspiracy charge, as a good lawyer can have an easier time defending me against a conspiracy charge verse me being caught physically holding a kilo of cocaine.