| Popis: |
A stereospecific rearrangement of a series of 1,2-cis-diol monotosylates is described. The 5-hydroxy-6-tosyloxy derivatives, 2, lead to the A-homo-B-norketones 3 and 4 and the 5-hydroxy-4-tosyloxy derivatives 11, 12 and 28 to the A-nor-B-homoketones 13, 14 and 29. Rearrangement of 3-acetoxy-5-hydroxy-4-tosyloxy derivatives 31 however, results in the 3-aldehydo-A-nor-steroids 32. ORD and NMR data are reported and used to assign preferred conformations to the 7-membered rings of the rearranged keto-steroids 3, 4, 13 and 14. |
