Institute of Pharmaceutical Chemistry, University of Szeged, Eötvös utca 6, 6720, Szeged, Hungary.
Mol Divers. 2010 Feb;14(1):59-65. doi: 10.1007/s11030-009-9143-y. Epub 2009 Apr 15.
(1R,2R,3S,4R)-2-Amino-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylic acid 1 was reacted with three aldehydes and two isocyanides in methanol, in water, and under solvent-free conditions to prepare enantiomeric beta-lactams via U-4C-3CRs. The yields in methanol were found to be from acceptable to good. High diastereoselectivities of the reactions were observed, and the diastereoisomers were successfully separated in most cases. In water or under solvent-free conditions, the yields were similar to those in methanol when the aldehyde was pivalaldehyde or propionaldehyde. The advantages of water are the facile isolation of the precipitated product and the shorter reaction time.
（1R,2R,3S,4R）-2-氨基-6,6-二甲基双环[3.1.1]庚烷-3-羧酸 1 与三种醛和两种异氰化物在甲醇中、水中和无溶剂条件下反应，通过 U-4C-3CRs 制备对映体β-内酰胺。在甲醇中的产率从可接受到良好。反应表现出高的非对映选择性，并且大多数情况下可以成功分离非对映异构体。在水中或无溶剂条件下，当醛为特戊醛或丙醛时，产率与甲醇中的产率相似。水的优点是易于分离沉淀产物和较短的反应时间。
