Enzymatic desymmetrisation of a cyclopentane-triol deriviative; enantiomerically pure cyclopentane-triol derivativesSyntheticPage 27 (2001)
Submitted 4th Jul 2001, published 5th Jul 2001
A contribution from the Caddick
Lipase AK (65mg, generously provided by Amano Enzyme Co.)
pH 7 phosphate buffer (made up from buffer tablets available from Fisher)
To the cyclopentene derivative is added the buffer followed by Lipase AK. The suspension is stirred at 30C for 70-80 hours until completion (TLC), then extracted 3 times with ethyl acetate, washed with water, dried over magnesium sulphate, filtered and concentrated. Purification is by column chromatography eluting with 15-20% EtOAc/PE
Enzymatic desymmetrisations are a very useful way of producing optically pure products; the advantage over a kinetic resolution is the potential for 100% yield, as compared with a theoretical maximum of 50% for a kinetic resolution. The downside is the substrate must have an axis of symmetry. In this instance, the desired enantiomer is obtained by selective hydrolysis of one of the acetates, but the opposite enantiomer can be obtained by making the substrate as its meso diol (ie removing the acetates) and then reacting it with vinyl acetate in the presence opf the same enzyme. Lipase AK seems to be quite specific to this reaction, but Lipase PS, also obtainable form Amano Enzyme Co. works with a wider range of substrates and is suitable for kinetic resolutions of a number of secondary alcohols, an example of which will appear in synthetic pages in due course.
1HNMR (300MHz, CDCl3) 0.00 (3H, s), 0.03 (3H, s), 0.81 (9H, s), 1.75 (1H, d), 1.98 (3H, s), 4.04 (1H, t), 4.39 (1H, s), 5.23 (1H, s), 5.72 (1H, d, J=6.0), 5.83 (1H, d, J=6.0)
Toyama, K.; Iguchi, S.; Oishi, T.; Hirama, M.; Synlett, 1995, 1243.
This page has been viewed approximately 224 times since records began.
Get CDX file (Choose "Open this file from its current location" TWICE)
SyntheticPagesTM are for use
exclusively by those with training and experience in synthetic chemistry. While contributors
are asked to identify hazards and to use methods designed to reduce risk, no formal hazard
or risk assessments are included, and these procedures must be conducted at one's own risk.
SyntheticPages, its editors, owners and associates do not warrant or guarantee the safety of
individuals using these procedures and hereby disclaim any liability for any injuries or damages
claimed to have resulted from or related in any way to the procedures herein. Copyright ©2005 Synthetic Pages
Comment on this page!
Registered users may add comments to other pages. If you have already registered, please
log in, otherwise you may
Back to List