Testosterone tetrahydropyranyl ether

Testosterone propionate, 409 Testosterone tetrahydropyranyl ether, 43 Testosterone tosylate, 445, 449... 

Testosterone 17-tetrahydropyranyl ether allowed to react with Li-bis(trimethyl-silyl)amide in tetrahydrofuran, then treated with er -butyldimethylchlorosilane product. Y 90%. M. Tanabe and D. F. Crowe, Chem. Commun. 1973, 564. 

On angular methylation with protection of the 3o -hydroxy group in the form of the tetrahydropyranyl ether, the furfurylidene derivative (180) formed the trans-C/D and the cis-C/D methyl derivatives (177) and (181), respectively, in a ratio of 1 3.8. Transacetylation, ozonolysis, and esterification of the trans-methyl derivative (177) led to the diester (178), the Dieckmann reaction of which followed by acid hydrolysis gave the hydroxy ketone (179). Oxidation of the 30 -hydroxy group of the latter and the introduction of a A -bond by bromination and dehydrobromination led to the yeast Saccharomyces cerevisiae by a known method [927], a mixture of the c -enantiomer of testosterone (182) and the Z-enantiomer of androstene-dione (183), which were separated chromatographically, was obtained with yields of 70 and 73%, respectively. The over-all yield of Z-testosterone (182) in this synthesis amounted to 2.9% on the (162) (twelve stages) and 1.1% on the unsaturated ketone (140) (16 stages) [921]. 

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