Olefin metathesis: remote substituents governing the stereoselectivity of 11-membered-ring formation.
[reaction: see text] Stereospecific RCM reaction of 7 (R1 = Me) results in the formation of (Z)-11-membered macrocycle 9c. Cascade RCM/ROM/RCM transformation of 7 (R1 = H) affords the thermodynamically more stable spirocycle product 12.
Vassilikogiannakis
Georgios
G
Department of Chemistry, University of Crete, 71409 Iraklion, Crete, Greece. vasil@chemistry.uoc.gr
Margaros
Ioannis
I
Tofi
Maria
M