2912-26-7

Upstream product

• 109576-60-5 19-oxoquebrachamine 
• 4724-62-3 (3¹S,6aR,9aR)-6a-ethyloctahydro-1H-pyrrolo[3,2,1-ij]quinolin-9(2H)-one 
• 6971-45-5 2-methoxyphenylhydrazine hydrochloride 
• 1263381-01-6 3-ethyl-5-bromo-2-pyrone 
• 503000-58-6 N-(6a-ethyl-decahydro-pyrrolo[3,2,1-ij]quinolin-9-ylidene)-N'-(2-methoxy-phenyl)-hydrazine 

Downstream Products

• 2447-50-9 (+)-deacetylaspidospermine 
• 466-46-6 vallesine 
• 466-49-9 aspidospermine 

Relevant academic research and scientific papers

Enantioselective Synthesis of (-)-Vallesine: Late-Stage C17-Oxidation via Complex Indole Boronation

The first enantioselective total synthesis of (-)-vallesine via a strategy that features a late-stage regioselective C17-oxidation followed by a highly stereoselective transannular cyclization is reported. The versatility of this approach is highlighted by the divergent synthesis of the archetypal alkaloid of this family, (+)-aspidospermidine, and an A-ring-oxygenated derivative, (+)-deacetylaspidospermine, the precursor to (-)-vallesine, from a common intermediate.

Divergent Asymmetric Total Synthesis of (+)-Vincadifformine, (-)-Quebrachamine, (+)-Aspidospermidine, (-)-Aspidospermine, (-)-Pyrifolidine, and Related Natural Products

A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (-)-quebrachamine, (+)-aspidospermidine, (-)-aspidospermine, (-)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C-E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A-B ring.

Total synthesis of (-)-aspidospermine via diastereoselective ring-closing olefin metathesis

(Matrix presented) An enantiocontrolled total synthesis of (-)-aspidospermine has been achieved. The key element of the strategy is the diastereoselective construction of the quaternary stereogenic center employing 1,4-asymmetric induction during the ring-closing olefin metathesis.