A convenient synthesis of oxandrolone through a regioselective Candida antarctica lipase-catalyzed transformation

Ferraboschi, Patrizia; Colombo, Diego; Prestileo, Paolo

doi:10.1016/s0957-4166(03)00593-7

Cited by 9 publications

(2 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Oxidation of the two hydroxyl groups in 7 to the corresponding carbonyl carbons present in 8 was achieved with PDC in DMF. The synthesis of a 3-keto-Δ 1 steroid intermediate by bromination at C2 followed by dehydrohalogenation of 8 was complicated by the fact that the treatment of 8 with phenyltrimethylammonium perbromide (PTAP) gave epimerization at C20. For that reason, the aldehyde group in 8 was oxidized to the corresponding carboxylic acid to give 9 , which was then submitted to thioesterification with N -acetylcysteamine to afford analogue 10a .…”

Section: Resultsmentioning

confidence: 99%

Isolation, Biological Significance, Synthesis, and Cytotoxic Evaluation of New Natural Parathiosteroids A−C and Analogues from the Soft Coral Paragorgia sp.

et al. 2008

View full text Add to dashboard Cite

Three unusual new steroid thioesters, parathiosteroids A-C (1a-3a), were isolated from the 2-propanol extract of the soft coral Paragorgia sp. collected in Madagascar. Their structures, determined by detailed spectroscopic analysis, were confirmed by synthesis and represent the first isolation of natural steroids bearing a C22 thioester in their side chain. These compounds displayed cytotoxicity against a panel of three human tumor cell lines at the micromolar level. The preparation of several analogues revealed structure/activity relationships in this type of steroids, for example, that the XCH2CH2NHCOCH3 moiety (X = S, O, NH) in the side chain is essential for the antiproliferative activity, and a low degree of oxidation in the A-ring results in higher bioactivity. These natural products could be biosynthetic intermediates in the steroid side chain degradation pathway involving activation with CoA and beta-oxidations.

show abstract

Section: Resultsmentioning

confidence: 99%

Isolation, Biological Significance, Synthesis, and Cytotoxic Evaluation of New Natural Parathiosteroids A−C and Analogues from the Soft Coral Paragorgia sp.

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Deacetylation of a steroidal 1,3-seco-2-nor-1,3-diol diacetate was unsuccessful with PCL and CRL, whereas CAL-B mediated alcoholysis in THF with 1-octanol afforded the 1-acetate (24 h, 70%) [127]. Deacetylation of a steroidal 1,3-seco-2-nor-1,3-diol diacetate was unsuccessful with PCL and CRL, whereas CAL-B mediated alcoholysis in THF with 1-octanol afforded the 1-acetate (24 h, 70%) [127].…”

Section: Steroid Estersmentioning

confidence: 99%

Lipase-Catalyzed Deacylation by Alcoholysis: A Selective, Useful Transesterification Reaction

Santaniello¹,

Casati²,

Ciuffreda

2006

COC

View full text Add to dashboard Cite

Alcoholysis is a transesterification reaction, according to which an ester RCOOR′ reacts with an alcohol R′′OH with formation of another ester RCOOR′′ and liberation of the alcohol R′OH. The deacylation may be catalyzed by a lipase in organic solvents and constitutes a useful step in the synthesis of complex molecules where different groups are present. The enzymatic deprotection procedure acquires a particular significance, considering the hydrophobic nature of the substrates and their solubility in organic solvents. In these non-conventional media lipases are still considerably active and a great variety of examples of regio-and chemoselectivity of the enzymatic deacylation have been reported. Application of resolution or asymmetrization procedures to the preparation of stereochemically pure products will also be examined and discussed. O AcO AcO OAc O AcO AcO OH Lipase-Catalyzed Deacylation by Alchololysis

show abstract

Biocatalyzed Regio‐ and Chemoselective Ester Cleavage: Synthesis of Bioactive Molecules

Barbayianni

Kokotos

2012

ChemCatChem

View full text Add to dashboard Cite

Biocatalysis is one of the greenest technologies for the synthesis of bioactive molecules, for which the presence of various functional groups requires selective protection or deprotection processes. The effective combination of protecting group techniques often results in additional chemical synthetic steps. At this point, enzymes can prove very valuable, as they help to circumvent several reaction steps, owing to the selectivity they show for a particular group. Specifically, carboxylic acid and alcohol functionalities, as well as esters, are of high importance for the biological properties of certain molecules. Esters are enzyme‐labile moieties, a characteristic that many drugs activity is based on. Ester cleavage is also required for synthesis, where beyond any doubt, the majority of reactions and conditions must be highly selective. This review aims to highlight a number of examples in the literature relative to regio‐ and chemoselective biocatalytic deprotection processes of the carboxyl and hydroxyl moieties, used in the synthesis of pharmaceuticals, bioactive molecules, and drug precursors.

show abstract

A convenient synthesis of oxandrolone through a regioselective Candida antarctica lipase-catalyzed transformation

Cited by 9 publications

References 14 publications

Isolation, Biological Significance, Synthesis, and Cytotoxic Evaluation of New Natural Parathiosteroids A−C and Analogues from the Soft Coral Paragorgia sp.

Isolation, Biological Significance, Synthesis, and Cytotoxic Evaluation of New Natural Parathiosteroids A−C and Analogues from the Soft Coral Paragorgia sp.

Lipase-Catalyzed Deacylation by Alcoholysis: A Selective, Useful Transesterification Reaction

Biocatalyzed Regio‐ and Chemoselective Ester Cleavage: Synthesis of Bioactive Molecules

Contact Info

Product

Resources

About