[portugal]

I put my sample through the polarimeter after all the resolution steps etc and obtained an optical purity of 150% which is not possible lol. However i am unsure as to what could of have contributed to such a high optical purirty i was told possibly a impurity with a higher specific rotation could have resulted in this but i cant think of such an impurity. Does anyone have any ideas for this very bad result?

ps.it would be great to get a 150%. wouldnt all organic chemists love that

[AWK]

You should ensure you are dealing with pure amine or its hydrochloride. They have different specific rotation and different molecular masses

[portugal]

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv5p0932

if someone could tell me what i am doing worng looking at this page on the web showing the % yeilds of the final amines i am getting either lower or higher yields when i do the calculations using their values to say if i had done exactly as what they did and got the same results.

what i am doing wrong for example on the first url for the final (S)-(-)...amine i am getting 6.9g/25g = 028% whilst they are getting 55%. what am i doing wrong here?

[Yggdrasil]

% yield is calculated using MOLES.  1 g of starting material will not necessarily yield 1 g of product because the molecular weights of the starting material and product are likely different.