Oxidations of 14α‐hydroxy‐5α‐cholestan‐3β‐yl acetate (5) with lead tetraacetate under thermal or photolytic conditions or in the presence of iodine proceed mainly by fragmentation of the C(13)−C(14) bond to give as the primary products the 13,18‐didehydro‐13,14‐seco derivative 6 and the (E )‐Δ12‐13,14‐seco ketone 11, respectively. Further transformations of these compounds under conditions of their formation afforded, in addition, the acetoxy derivatives 7 – 9 (from 6), and the D‐homo‐C‐nor compound 12 and (12R,13R)‐epoxide 13 (from 11). Unexpectedly, the photolytic lead‐tetraacetate oxidation of 5 resulted partly (to ca. 20%) in a reversible fragmentation involving scission and recombination of the C(8)−C(14) bond followed by formation of the 14β,22‐ether 10. Possible mechanisms for the observed transformations are discussed.
TY - JOUR
AU - Bjelaković, Mira
AU - Lorenc, Ljubinka
AU - Pavlović, Vladimir D.
AU - Mihailović, Milhailo Lj.
AU - Tinant, Bernard
AU - Declercq, Jean-Paul
AU - Kalvoda, Jaroslav
PY - 1999
UR - https://cer.ihtm.bg.ac.rs/handle/123456789/4184
AB - Oxidations of 14α‐hydroxy‐5α‐cholestan‐3β‐yl acetate (5) with lead tetraacetate under thermal or photolytic conditions or in the presence of iodine proceed mainly by fragmentation of the C(13)−C(14) bond to give as the primary products the 13,18‐didehydro‐13,14‐seco derivative 6 and the (E )‐Δ12‐13,14‐seco ketone 11, respectively. Further transformations of these compounds under conditions of their formation afforded, in addition, the acetoxy derivatives 7 – 9 (from 6), and the D‐homo‐C‐nor compound 12 and (12R,13R)‐epoxide 13 (from 11). Unexpectedly, the photolytic lead‐tetraacetate oxidation of 5 resulted partly (to ca. 20%) in a reversible fragmentation involving scission and recombination of the C(8)−C(14) bond followed by formation of the 14β,22‐ether 10. Possible mechanisms for the observed transformations are discussed.
PB - Wiley
T2 - Helvetica Chimica Acta
T1 - 13,14-Seco-steroids: A New Type of Modified Steroids Containing a Nine-Membered Ring
VL - 82
IS - 5
SP - 707
EP - 721
DO - 10.1002/(SICI)1522-2675(19990505)82:5<707::AID-HLCA707>3.0.CO;2-O
ER -
@article{
author = "Bjelaković, Mira and Lorenc, Ljubinka and Pavlović, Vladimir D. and Mihailović, Milhailo Lj. and Tinant, Bernard and Declercq, Jean-Paul and Kalvoda, Jaroslav",
year = "1999",
abstract = "Oxidations of 14α‐hydroxy‐5α‐cholestan‐3β‐yl acetate (5) with lead tetraacetate under thermal or photolytic conditions or in the presence of iodine proceed mainly by fragmentation of the C(13)−C(14) bond to give as the primary products the 13,18‐didehydro‐13,14‐seco derivative 6 and the (E )‐Δ12‐13,14‐seco ketone 11, respectively. Further transformations of these compounds under conditions of their formation afforded, in addition, the acetoxy derivatives 7 – 9 (from 6), and the D‐homo‐C‐nor compound 12 and (12R,13R)‐epoxide 13 (from 11). Unexpectedly, the photolytic lead‐tetraacetate oxidation of 5 resulted partly (to ca. 20%) in a reversible fragmentation involving scission and recombination of the C(8)−C(14) bond followed by formation of the 14β,22‐ether 10. Possible mechanisms for the observed transformations are discussed.",
publisher = "Wiley",
journal = "Helvetica Chimica Acta",
title = "13,14-Seco-steroids: A New Type of Modified Steroids Containing a Nine-Membered Ring",
volume = "82",
number = "5",
pages = "707-721",
doi = "10.1002/(SICI)1522-2675(19990505)82:5<707::AID-HLCA707>3.0.CO;2-O"
}
Bjelaković, M., Lorenc, L., Pavlović, Vladimir D., Mihailović, M. Lj., Tinant, B., Declercq, J.,& Kalvoda, J.. (1999). 13,14-Seco-steroids: A New Type of Modified Steroids Containing a Nine-Membered Ring. in Helvetica Chimica Acta
Wiley., 82(5), 707-721.
https://doi.org/10.1002/(SICI)1522-2675(19990505)82:5<707::AID-HLCA707>3.0.CO;2-O
Bjelaković M, Lorenc L, Pavlović V, Mihailović ML, Tinant B, Declercq J, Kalvoda J. 13,14-Seco-steroids: A New Type of Modified Steroids Containing a Nine-Membered Ring. in Helvetica Chimica Acta. 1999;82(5):707-721.
doi:10.1002/(SICI)1522-2675(19990505)82:5<707::AID-HLCA707>3.0.CO;2-O .
Bjelaković, Mira, Lorenc, Ljubinka, Pavlović, Vladimir D., Mihailović, Milhailo Lj., Tinant, Bernard, Declercq, Jean-Paul, Kalvoda, Jaroslav, "13,14-Seco-steroids: A New Type of Modified Steroids Containing a Nine-Membered Ring" in Helvetica Chimica Acta, 82, no. 5 (1999):707-721,
https://doi.org/10.1002/(SICI)1522-2675(19990505)82:5<707::AID-HLCA707>3.0.CO;2-O . .
