Optically Active Quaternary Carbon Centers from the Photoaddition of Chromium-Alkoxycarbene Complexes and Optically Active Thiazolines

Article abstract of DOI:10.1021/jo00031a025

The photolytic reaction of chromium-alkoxycarbene complexes with valine-derived, optically active thiazolines produced optically active β-lactam penam derivatives in fair to good yield and with high diastereoselectivity.In most cases alcoholysis of the β-lactam followed by solvolysis of the thiazolidine ring produced optically active quaternary centers having carbon substituents in four different oxidation states - alkane, alkoxy, aldehyde, and ester.The absolute configuration of the stereogenic center could be inverted by a sequence of redox manipulations of the ester and aldehyde group, making either enantiomer available from the same precursor.