Collect. Czech. Chem. Commun. 1979, 44, 128-144

Cyclization of 17-ethylenedioxy-3α,5-cyclo-6,7-seco-5α-androstane-6,7-diol

Helena Velgováa, Dietrich Zeiganb, Günther Engelhardtb and Antonín Trkaa

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia
b Academy of Sciences of the GDR, Central Institute of Physical Chemistry, 1199 Berlin-Adlershof, G.D.R.


Intramolecular cyclization of 17-ethylenedioxy-3α,5-cyclo-6,7-seco-5α-androstane-6,7-diol (I) on treatment with p-toluenesulphonyl chloride in pyridine gives 17-ethylenedioxy-3α,5-cyclo-B-homo-7-oxa-5α-androstane (III) and 17-ethylenedioxy-3,5-methylene-6-oxaandrostane (II). The cyclic ethers II and III after deketalization and treatment with boron trifluoride etherate in acetic anhydride yield 3β,7-dihydroxy-6,7-secoandrost-5-en-17-one (XIV) along with a small quantity of 3β,5-cyclo-A-homo-6-oxa-5β-androstane-17-one (XIII). Proof of the structures in question is based on IR, 1H NMR, 13C NMR and mass spectrometric data.