Diastereoselective synthesis of trans-1,2-disubstituted cyclopropanols from homoallyl or bis-homoallyl esters via tandem intramolecular nucleophilic acyl substitution and intramolecular carbonyl addition reactions mediated by Ti(OPr-i)4 / 2 i-PrMgBr reagent
作者:Aleksandr Kasatkin、Fumie Sato
DOI:10.1016/0040-4039(95)01208-y
日期:1995.8
Reactions of homoallyl or bis-homoallyl esters with Ti(OPr-i)4/2 i-PrMgBr reagent resulted in intramolecular nucleophilic acyl substitution reaction and successive intramolecular carbonyladdition reaction providing trans-1,2-disubstituted cyclopropanols stereoselectively in excellent yields.
Six- and seven-membered pentacarbonyl(2-oxacycloalkenylidene) chromiumcomplexes 17 and 6 have been synthesized in moderate to good yields from alkenyloxy(methyl)carbenecomplex precursors applying an α-alkylation/ruthenium based ring closing metathesis sequence. The ring-closure is hampered for β-alkylated vinylcarbene complexes which may undergo competing intermolecular cross metathesis at the alkenyloxy