Inversion of ring D of gibberic acid
Abstract
8ξ-Amino-10β-hydroxymethyl-1,7-dimethyl-4bα,7α-gibba-1,3,4a(10a)-triene (IVa) was prepared from gibberic acid and deaminated. The products included 8α-hydroxy-10β-hydroxymethyl-1,8β-dimethyl-4bα-gibba-1,3,4a(10a)-triene (Va) and its 8-epimer (Vb). Oxidation of the diol (Va) and related compounds gave not only the expected acids [e.g.(Vc)], but also the corresponding 10-ketones [e.g.(VIa)] by loss of the 10-hydroxymethyl group.