The structure of (+)-4-hydroxysedamine 1 and (+)-4-hydroxyallosedamine 2, two new minor alkaloids from Sedum acre, are reported. 1 and 2 were synthesized, and their absolute configuration established, via the optically pure tetrahydro 1,3-oxazines 17 and 18. Sedum acre contains a variety of piperidine alkaloids. In our continuing investigation of Sedum alkaloids we reported recently the isolation of sedacrine, the major alkaloid, and a number of related bases. Extensive fractionation, by countercurrent distribution and preparative chromatography, of a mixture of more polar alkaloids from this species has now led to the isolation of some new minor bases bearing an hydroxyl group on the piperidine ring. The structures and the syntheses of two of these (+)-4-hydroxysedamine 1 and (+)-4-hydroxyallosedamine 2 are reported in the present communication.