[kriggy]

I wonder if anyone of you used enzymes in lab? Im thinking about trying some DKR because I resolution by crystalization didnt work and converting my racemate into diastereomers and running collumn is pain in the ass and cant scale it enough.

Its obvious that it can be used to hydrolyze the ester but does it work the other way around? Does it require any specific handling of the enzyme ? And last: there seems to be tons of different lypases available at sigma but how does one choose which one to use?

[Babcock_Hall]

I use enzymes in kinetic studies, but I have never used them synthetically.  There are several books on this subject, including one by Wong and Whitesides.  IIRC Whitesides' lab used enzymes in some of their work on resolving amino acids.

[pgk]

According to the literature, lipases can be used synthetically for both esterification and ester hydrolysis. But as being enzymes, lipases are sensible to the steric hindrance; which means that their successful use as a general method, is not guaranteed and that the obtained result depends on the particular structure of the ester.

[rolnor]

I was doing some work with opticaly active material and lipase. The hydrolysis worked fine with a simple small ester like mono-acetyl glycerol but failed with my, more stericaly hindered ester. I think it is time-consuming working out a procedure involving enzyme and for me it is a last resort.

[kriggy]

So you think its more time consuming than optimizing resolution by crystalization?

[rolnor]

I dont know that, I have not worked with fractional crystalization.

[phth]

Can it be crystallized as a salt? Maybe a chiral additive could solve the problem e.g. an amine or a carboxylate... Enzyme solution seems complicated i.e. your compound must be soluble in water, or it will take a really long time. Your product may significantly hydrolyze if it is an ester.  OR you could use a chiral auxillary and there are no problems of racemic mixtures

[kriggy]

I dont know if it can be crystalized as a salt. I did try it but without much succes. So I did convert the acid into chiral oxazoline and separated them with collumn and then hydrolyzed back.
Im not sure what do you mean by the chiral additive