Synthetic steroids. Part IV. The reaction of 3β-hydroxy-5α-cholest-1-ene and 3β-hydroxycholest-4-ene with toluene-p-sulphonyl chloride in pyridine

Abstract

The reaction of 3β-hydroxy-5α-cholest-1-ene with toluene-p-sulphonyl chloride in pyridine does not yield the expected Δ¹-3β-toluene-p-sulphonyl ester but results directly in the production of N-(5α-cholest-1-en-3α-yl)-pyridinium tosylate (44%) and 1α,5-cyclo-5α-cholest-2-ene (22%). Similar rearrangements of the allylic alcohols androst-1-en-3β-ol and 17β-methoxyandrost-1-en-3β-ol are also reported.

An attempted preparation of cholest-4-ene 3β-toluene-p-sulphonyl ester yielded directly a mixture of cholesta-3,5-diene (24%), 3α,5-cyclo-5α-cholest-6-ene (3%), N-(cholest-4-en-3α-yl)pyridinium tosylate (28%), the balance of the reaction product being cholest-4-en-3β-ol.

The Δ¹-3β-alcohol and the Δ⁴-3β-alcohol systems have both been shown to be unstable towards analysis by gas chromatography, each compound decomposing into a mixture of a cyclo-steroid and a diene.

The visible absorption spectra of the complexes formed between various cyclo-steroids and tetranitromethane are reported.