A highly enantioselective benzothiepine synthesis
A highly enantioselective synthesis of benzothiepine 1a has been accomplished via an enantioenriched sulfoxide intermediate obtained by asymmetric oxidation with a chiral oxaziridine in 89:11 er. The key step is a thermodynamically controlled asymmetric cyclization reaction that produces two new stereogenic centers. The (4R,5R) isomer 1a was obtained in 98:2 er.
Wang
CC
Searle Research & Development, Monsanto Company, St. Louis, Missouri 63017, USA.
Li
JJ
Huang
HC
Lee
LF
Reitz
DB