Diastereoselective Synthesis of γ- and δ-Lactams from Imines and Sulfone-Substituted Anhydrides
نویسندگان
چکیده
Sulfone-substituted γ- and δ-lactams have been prepared in a single step with high diastereoselectivity. Sulfonylglutaric anhydrides produce intermediates that readily decarboxylate to provide δ-lactams with high diastereoselectivity. Substituents at the 3- or 4-position of the glutaric anhydride induce high levels of stereocontrol. Sulfonylsuccinic anhydrides produce intermediate carboxylic acids that can be trapped as methyl esters or allowed to decarboxylate under mild conditions. This method has been applied to a short synthesis of the pyrrolizidine alkaloid (±)-isoretronecanol.
منابع مشابه
Diastereoselective synthesis of potent antimalarial cis-β-lactam agents
Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...
متن کاملStereoselective synthesis of indoline, tetrahydroquinoline, and tetrahydrobenzazepine derivatives from o-bromophenyl N-tert-butylsulfinyl aldimines.
The diastereoselective addition of an allylic indium intermediate to chiral o-bromophenyl sulfinyl imine 4 proceeded with good levels of diastereoselectivity. The resulting homoallylic amine derivatives were transformed into lactams 7 and 12, which upon copper-mediated intramolecular N-arylation led to the formation of benzo-fused 1-azabicyclo[j.k.0]alkanes 8 and 13. Benzo-fused 2-allyl-substit...
متن کاملAccess to enantiopure 4-substituted 1,5-aminoalcohols from phenylglycinol-derived δ-lactams: synthesis of Haliclona alkaloids.
LiNH2BH3-promoted reductive opening of 8-substituted phenylglycinol-derived oxazolopiperidone lactams leads to enantiopure 4-substituted-5-aminopentanols, which are used as starting building blocks in the synthesis of the Haliclona alkaloids haliclorensin C, haliclorensin, and halitulin (formal). The starting lactams are easily accessible by a cyclocondensation reaction of (R)-phenylglycinol wi...
متن کاملDiastereoselective synthesis of potent antimalarial cis-β-lactam agents
Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...
متن کاملCatalytic, enantio- and diastereoselective synthesis of γ-butyrolactones incorporating quaternary stereocentres.
A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (γ-butyrolactone) derivatives is reported.
متن کامل