AbstractWe have isolated from the carpophores ofBoletus satanas Lenz(Basidiomycetae) (2S,4S)‐(+)‐γ‐hydroxynorvaline (1) and (2S,4R)‐(−)‐γ‐hydroxynorvaline (2). The chirality of each diastereomer has been determined by chemical synthesis starting from optically active precursors and by application of different chiroptical methods. Gaschromatographic separation of the derived diastereomeric N‐[(S)‐α‐methoxypropionyl]‐lactones reveals that the optical purity of natural2is 88% whereas1exists as a partial racemate: (2S,4S): (2R,4R) = 3:2.Muscarinecould not be detected in the carpophores ofB. satanas, contrary to some literature data but basic substances of unknown structure are pres