Influence of N-amino protecting group on aldolase-catalyzed aldol additions of dihydroxyacetone phosphate to amino aldehydes
- 作者：Jordi Calveras ; Jordi Bujons ; Teodor Parella ; Ramon Crehuet ; Laia Espelt ; Jesú ; s Joglar and Pere Clapé ; s
- 关键词：DHAP dependent aldolases ; Aldol additions ; Fmoc group ; Boc group ; PhAc group ; Penicillin amidase
- 刊名：Tetrahedron
- 出版年：2006
- 期刊代码：107_00404020
- 类别：ch
- 出版时间：13 March 2006
- 卷：62
- 期：11
- 页码：2648-2656
- 文件大小：198 K
摘要
This work examines the influence of N-protecting groups on the conversion and stereoselectivity of dihydroxyacetone phosphate (DHAP) dependent aldolase-catalyzed aldol additions of DHAP to N-protected-3-aminopropanal. Phenylacetyl-(PhAc-), tert-butyloxycarbonyl- (tBoc-) and fluoren-9-ylmethoxycarbonyl- (Fmoc-)-3-aminopropanal were evaluated as substrates for d-fructose 1,6-bisphosphate aldolase from rabbit muscle (RAMA), and l-rhamnulose-1-phosphate aldolase (RhuA) and l-fuculose-1-phosphate aldolase (FucA), both from Escherichia coli. Using PhAc and tBoc ca. 70%conversions to the aldol adduct were achieved, whereas Fmoc gave maximum conversions of ca. 25%. The stereoselectivity of the DHAP-aldolases did not depend on the N-protected-3-aminopropanal derivative. Moreover, inversion of FucA stereoselectivity relative to that obtained with the natural l-lactaldehyde was observed. Both N-PhAc and tBoc adduct product derivatives were successfully deprotected by penicillin G acylase (PGA)-catalyzed hydrolysis at pH 7 and by treatment with aqueous TFA (6%v/v), respectively. However, the corresponding cyclic imine sugars could not be isolated, presumable due to the presence of a highly reactive primary amine and a keto group in the molecule, which lead to a number of unexpected reactions.