By fragmentation-rearrangement of 12-tosylhydrazones

Similarly, 11-oxohecogenin p-toluenesulfonylhydrazone (152) is converted to C-nor-D-homo-11-ketone (153). 

In the preparation of C-nor-D-homosteroid hormone analogs Mitsuhashi and Harada extended the Bamford-Stevens rearrangement to the cholanic acid series. Treatment of 3a-hydroxy-12-oxocholanic acid /j-toluene- 

Since alkaline decomposition of p-toluenesulfonylhydrazones of steroid 12-ketones leads directly to 14(13 I2) jr e -13(17)-enes whereas solvolysis of 12j5-mesylates gives mixtures of 13(18)- and 13(17)-enes, the former approach is preferred for the preparation of C-nor-D-homosteroids. If the particular system under consideration is not stable to base at elevated temperatures, the milder solvolysis method could be used. Either approach starts with a 12-oxygenated steroid. Additional base-stable functional groups should be compatible under the conditions for the rearrangement process. 

This product is identical with the 3-acetate of the minor product formed in the solvolysis of rockogenin 3-methyl succinate-12j5-mesylate (144a). 

Prepared by dissolving 1 ml of concentrated fluoro boric acid (ca. 19 A) in 100 ml of anhydrous 3 1 diethyl ether-methylene dichloride solution [c/. M. Neeman, M. C. Caserio, J. D. Roberts and W. S. Johnson, Tetrahedron, 6, 36 (1959)]. 

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VII. 14(13 -> 12aH)y46eosteroids (C-Nor-D-Homo Steroids) / 400 By solvolysis of 12/ -methylsulfonyloxy steroids / 400 By fragmentation-rearrangement of 12-tosylhydrazones / 402... 

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