I took DAT last wednesday...even before taking orgo II.
Now I am taking orgo II in summer class.
I was so worried about orgo...However, I tried to memorize some important rxns(Grignards, Kolbe, tautomeriam...) in later part of orgo without understanding mechanism and I did very well in orgo. Of course I believe I was super lucky.
Just keep concentrating on memorizing some important rxn products and reactants. they don't usuallly deal with the mechanisms.
In IR spectrum, you can just understand some important peaks(alcohol, C=O....) and I saw the one question about H NMR question which dealt with Singlet, Doublet....