New synthesis of fused tricyclic 2-azetidinones using stereoselective allylation of cis-4-formyl-β-lactams and intramolecular Diels-Alder reaction
作者:Benito Alcaide、Pedro Almendros
DOI:10.1016/s0040-4039(98)02513-1
日期:1999.1
Tin(IV) chloride promoted addition of allyltrimethylsilane to cis-4-formyl-2-azetidinones 1 gives 4-[(1′-hydroxy)homoallyl]-β-lactams 2 with excellent stereoselectivities. The mesylates of alcohols 2 are used for the diastereoselective preparation of both 4-butadienyl-2-azetidinones 6 and fused tricyclic β-lactams 3 through a tandem one-pot elimination-intramolecular Diels-Alder reaction.