(6S)-trans-(-)-1-(6,7-dihydro-6-hydroxy-5,5-dimethyl-2-nitro-5H-thieno(3,2-b)pyran-7-yl)-2-piperidinone
(6s)-trans-(-)-1-(6,7-dihydro-6-hydroxy-5,5-dimethyl-2-nitro-5h-thieno(3,2-b)pyran-7-yl)-2-piperidinone