While semisynthesis is a common platform for medicinal investigation of steroidal systems, varying the nature of substitution and stereochemistry at C9 and C10 remains challenging. It is demonstrated here that de novo synthesis, enabled by a metallacycle-centered annulation reaction, provides a uniquely effective means of addressing this problem. In short, double asymmetric Friedel-Crafts cyclization proved most effective for establishing - relative stereochemistry (with respect to C13), while an intramolecular Heck reaction reliably delivered the - diastereomers with high selectivity. In addition, these studies reveal that this oxidative rearrangement is effective for establishing a C10 quaternary center boasting variable alkyl or aryl substitution.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7518127 | PMC |
| http://dx.doi.org/10.1021/acs.orglett.0c02358 | DOI Listing |
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