Transformation of 19-oximino derivatives

Bartonand Wolft achieved a similar transformations after introduction of a 5,6-double bond by zinc reduction of a 5,6-halohydrin. 

Note 1. The same result is obtained when the corresponding 19-oxime is used as starting material, instead of the nitroso dimer. 

19-oximes (present in the reaction mixture as 6,19-hemiacetals and their 

Although 3y5-hydroxy-A -l9-aldehydes can be obtained from the corresponding oxime by acid treatment, the most efficient method for the production of A -19-aldehydes is nitrosation of the oximes followed by zinc reduction of the 5a-halo hemiacetal.  

Similarly 11,19-hemiacetals have been prepared from lljS-hydroxy-19-16 

---

III. Preparation of 19-Norsteroids from 19-Substituted Steroids / 264 Transformations of 6(3, 19-ethers / 264 Transformation of 19-oximino derivatives / 268 Removal of the C-10 substituent / 272 Summary and procedures for 19-norsteroids / 278... 

---