Tosylhydrazones reaction with active

Two procedures have been devised for the synthesis of a novel class of cyclosteroids, the 4a,6a-cyclo-5/8-derivatives (190). Carbenoid decomposition (NaOMe 160 °C) of the tosylhydrazone (187) gave the unsaturated acid (188). Copper-catalysed decomposition of the derived diazo-ketone (189) gave the desired 4a,6a-cyclo-ketone (190) by a keto-carbene addition to the 5,6-double bond. A more satisfactory synthesis proceeded from the 6/3-tosylate (191), which gave the 4a,6a-cyclosteroid in high yield on reaction with base (KO Bu-HO Bu). Several hormone analogues with the 4a,6a-cyclo modification were devoid of biological activity. ... 

Some 2-deoxy-analogues of rubrosterone have been reported.73 The synthesis commenced with a Bamford-Stevens reaction upon 3/3,17/3-diacetoxyandrost-5-en-7-one tosylhydrazone to yield the corresponding 5,7-diene. Successive chromic acid and selenium dioxide oxidation of this diene furnished the 2-deoxyrubrosterones (177 R1 = OAc, R2 = H, R3 = OH, X= 17/3-0Ac,H 5a-H) and (177 R = OAc, R2 = R3 = H, X = 17/3-OAc,H 5a-H) respectively. Alkaline hydrolysis of the latter derivative afforded an A-homo-B-nor-steroid (178). The rubrosterone (177 R1 = R2 = R3 = OH, X = O 5/3-H), which possesses antidiabetic activity, has been prepared by oxidative degradation of the cholestene (179), itself obtained from ecdy-sterone.74... 

The reaction of organoboranes with carbon-nitrogen multiple bonds always leads to aminoborane derivatives through a hard-hard interaction. Hydro-boration of nitriles with optically active diisopinocampheylborane (43) constitutes a key step in an asymmetric synthesis of amino acids (44). Carbonyl compounds are deoxygenated via hydroboration of their tosylhydrazones (45). 

Benzvalene (807) is now readily available and its reactions are being actively explored. Cycloadditions to the double bond can be effected without opening the bicyclobutane. Thus the dichloroketen adduct could be reduced with PhgSnH to (808) and the tosylhydrazone of this treated with a strong non-nucleophilic base to give (809) in 50 % yield. Attempts to open this to (810) by heat or Ag" catalysis failed. ... 

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