Dušan Miljković

Synthesis, X-ray crystal structures and biological activity of 16-amino-17-substituted-D-homo steroid derivatives.

D-Homo derivatives in the androstane and estrane series, 12-19, were synthesized by a fragmentation-cyclization reaction of 16-oximino-17-hydroxy-17-substituted derivatives 3-9, or by cyclization of the corresponding D-seco derivatives 20-26. The structures were confirmed by X-ray analysis of compounds 12 and 16. Preliminary assessment of inhibitory effects of D-homo derivatives from androstane series towards aromatase, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17 alpha-hydroxylase/C17-20 lyase (P450c17) and 17 beta-HSD indicated much lower inhibitory potential compared to previously tested activity of another type of D-modified steroids, namely D-seco derivatives. Also, assessment of potential antiestrogenic activity of derivatives from estrane series showed absence of such an activity.

A novel route to 2-deoxy-2-iodo-d-mannopyranose derivatives

1,5-Anhydro-2-deoxy-D-hex-1-enitols are versatile synthons’*2. Various functional groups, such as chloro3, fluoro4-7, bromo8, or iodo’-I’, may be introduced at position 2 by either direct or indirect addition of suitable agents across the double bond. Iodination of o-glucal triacetate, using iodine and silver benzoate in dry benzene9*10, iodine and silver acetate in methanol’, N-iodosuccinimide in dry methanol’*, or iodonium bis(2,4,6-trimethylpyridine)perchlorate12, have been described, corresponding to the formal addition of alkyl or acyl hypoiodite across the double bond. However, the formation of free 2-deoxy-2-iodo sugars has not been described hitherto. We now report a formal electrophilic addition of “hypoiodous acid” to 3,4,6-tri0-acetyl-o-glucal’3 (1) and 3,4-di-0-acetyl-6-0-tosyl-D-glucal’4 (2). Depending on the buffer system used and the pH, a mixture of the 2-deoxy-2-iodo esters 3 of 5 together with the corresponding 2-deoxy-2-iodo sugars 4 or 6, or only 4 or 6, were obtained. The compounds obtained could be used for the preparation of 2-deoxy sugars or Brigl’s anhydrides. Thus, treatment of 1 or 2 with iodine in tert-butyl alcohol in the presence of acetate buffer (pH 5, room temperature, 3 h) gave a mixture of the 2-deoxy-2iodo-manno-esters 3 or 5 together with the corresponding Zdeoxy-Ziodo-a-o-mannopyranose derivatives 4 or 6, in the ratio 3 : 1. However, when this reaction was carried out in the presence of a phosphate or carbonate buffer (pH 6-7, room temperature, 3 h), the 2-deoq&iodo-a-D-mannopyranose derivatives 4 or 6 were the only isolable products (50-60%). The structures of 3-6 were confirmed by the NMR data (Table I> and [cu], values. The above procedure for the preparation of the 2-deoxy-2-iodo-cu-D-manno-

A novel rearrangement of steroidal α-hydroxy oximes

Abstract By the action of acidic titanium trichloride upon 16-oximino-17α-benzyl-17β-hydroxy derivatives in the androstane and estrane series the 16-oxo-17β-benzyl-17α-hydroxy derivatives 6 and 7 with inversed configuration at C 17 were obtained. A mechanism for this novel rearrangement is proposed.

Synthesis and estrogen activity screening of some new D-secoestrone derivatives.

Five new D-secoestrone derivatives were synthesized, starting from 3-methoxy-17-hydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile. Newly synthesized compounds showed a complete loss of estrogenic activity.

Synthesis and unusual beckmann fragmentation reaction of syn-3-Methoxy-6α,17β-Dihydroxyestra-1,3,5(10)-trien-7-one oxime

Abstract Sodium borohydride reduction of anti-3-methoxy-17β-hydroxyestra-1,3,5(10)-trien-6,7-dione 7-oxime (4a) afforded syn-3-methoxy-6α,17β-dihydroxyestra-1,3,5(10)-trien-7-one oxime (5), which in thionyl chloride at −18 °C undenvent Beckmann fragmentation reaction to the unexpected 3-methoxy-6-oxo-17β-hydroxy-6.7-secoestra-1.3.5(10)-trien-7-nitrile (6). A mechanism of this fragmentation process was proposed.

Conversion of d-xylose to protected d-lyxose derivatives and to d-lyxose, via the corresponding 1,2-anhydride

Abstract Acid hydrolysis of 3,5-di- O -benzyl-1,2- O -cyclohexylidene-α- d -xylofuranose gave the corresponding lactol, which was subsequently converted to the 3,5-di- O -benzyl-2- O -mesyl- d -xylofuranose. This compound readily reacted with sodium methoxide, sodium benzylate or sodium hydroxide (presumably via the corresponding 1,2-anhydride) to give the protected d -lyxofuranosides. These compounds were finally converted to methyl α- d -lyxopyranoside or to d -lyxose.

Some new ring-D seco steroids

Abstract The Beckmann fragmentation product, 3-methoxy-17-oxo-16,17-secoestra-1,3,5(10)-trien-16-nitrile ( 2 ) has been reduced by LAH giving the expected 3-methoxy-17-hydroxy-16,17-secoestra-1,3,5(10-trien-16-amine hydrochloride ( 3 ) and 3-methoxy-17-oxa- D -homoestra-1,3,5(10)-trien-16-ol ( 4 ), by a presumed neighbouring group participation of 17-OH group in the intermediary formed 16-imino derivative ( A ). The structure of 4 has been proved by an alternative synthetic route by reducing 3-methoxy-17-oxa- D -homoestra-1,3,5(10)-trien-16-one ( 7 ) with di-iso-butylaluminium hydride.

Stereospecific synthesis of (+)-oxybiotin from D-xylose.

A new 14-step synthesis of (+)-oxybiotin, an oxygen analogue of (+)-biotin, was achieved starting from D-xylose by use of selected 2,5-anhydro sugar derivatives as key intermediates.

Ozonation of 3β-acetoxy-5α-chloro-cholestane in solution. X-ray study of 3β-acetoxy-5α-chloro-14-cholestene-ozonide.

Abstract A selected saturated steroid derivative has been subjected to ozonation in solution. As the main reaction product 14,15-ozonide has been isolated in crystalline form whose structure has been unambiguously confirmed by the X-ray difraction method.

A novel fragmentation-cyclization reaction of steroidal α-hydroxy oximes

Abstract By a novel “one pot” fragmentation-cyclization reaction 17β-hydroxy-17α-substituted-16-oximino derivatives in the androstane and estrane series were converted to a new type of D-homo derivative.