4,7-didehydro-7-deoxyphysalin L 生成 (1S,2S,3R,5S,6R,14R,15S,18S,21S,22R,25S)-5,18-dihydroxy-1,14,21,25-tetramethyl-4,20,23-trioxaheptacyclo[20.3.1.12,5.03,18.03,21.06,15.09,14]heptacosane-13,19,24,27-tetrone
(1S,2S,3R,5S,6S,7R,14R,15S,18S,21S,22R,25S)-5,7,18-trihydroxy-1,14,21,25-tetramethyl-4,20,23-trioxaheptacyclo[20.3.1.12,5.03,18.03,21.06,15.09,14]heptacosa-8,11-diene-13,19,24,27-tetrone 生成 4,7-didehydro-7-deoxyphysalin L
The previously proposed structure of an acid-induced dehydration product of physalin A, a 13,14-seco-16,24-cyclosteroid, is revised as having a new carbon skeletal structure named neophysalin. The reaction from physalins to neophysalins proceed via a kind of the benzilic acid rearrangement.