Synthesis of “Garner” Aldehyde-Derived Cyclopropylboronic Esters
作者:Jörg Pietruszka、Andreas Witt、Wolfgang Frey
DOI:10.1002/ejoc.200300220
日期:2003.8
The “Garner” aldehyde has been used as a common intermediate for the preparation of the corresponding alkyne 7 and the alkenylboronic esters 12−16 (24−80%). Diastereoselective cyclopropanation afforded cyclopropylboronic esters 17−20 (60−84%, dr 22:78 to 92:8), the configurations of which were determined by chemical correlation (cyclopropanols 22), X-ray structural analysis (of 21a), and characteristic