L. T. Quyen, H. Ripperger, G. Adam
Feb 12, 1993
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0
Influential Citations
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Citations
Journal
European Journal of Organic Chemistry
Abstract
(22R,23S,25R)-N-Chloro-22,26-epiminocholest-5-ene-3β,16β,23-triol (11) and its 3,16,23-O-triacetyl derivative 15 were prepared from solasodine (1). Treatment of 11 or 15 with sodium methanolate yielded the 22,23-secoaldehyde 16 as major product (Grob fragmentation) and (23S)-23-hydroxysolasodine (2) as minor product (Ruschig reaction). Hydrolysis of 16 with methanolic hydrochloric acid afforded 16β,22-epoxy-23,24-dinorchol-5-ene-3β,22β-diol (17) and its 22-O-methyl derivative 18, the 3-O-acetate 19 of which was oxidized to the known acetyldiosgenin lactone (20), thus confirming the structures of 16–19. Compound 2 was shown to be identical in every respect with a rare spirosolane alkaloid, recently isolated from some Solanum species. Photolysis of (22R,23S,25R)-3β,16β-diacetoxy-N-chloro-22,26-epiminocholest-5-en-23-ol (10) yielded also via 22,23-carbon-carbon cleavage (20S)-3β,16β-diacetoxypregn-5-ene-20-carbaldehyde (21) as major product, which was converted by treatment with methanolic hydrochloric acid into the compound 18.