Toward the Synthesis of Paspaline-Type Indole-Terpenes: Stereoselective Construction of Core Scaffold with Contiguous Asymmetric Quaternary Carbon Centers

Ichiro Hayakawa*, Naochika Matsumaru, and Akira Sakakura* 
J. Org. Chem.2021, ASAP (Published online: July 7, 2021) 
DOI: 10.1021/acs.joc.1c01193

The core scaffold of paspaline-type indole-terpenes was synthesized by using the House–Meinwald rearrangement as a key step. Rearrangement of the epoxide methyl group in the precursor with methylaluminum bis(4-bromo-2,6-di- tert-butylphenoxide) as a Lewis acid proceeded smoothly to construct contiguous asymmetric quaternary carbon centers by a 1,2-chirality transfer.