Stereoselective synthesis of highly substituted bicyclic γ-lactones using homoaldol addition of 1-(1-cycloalkenyl)methyl carbamates

TY - JOUR

T1 - Stereoselective synthesis of highly substituted bicyclic γ-lactones using homoaldol addition of 1-(1-cycloalkenyl)methyl carbamates

AU - Özlügedik, M.

AU - Kristensen, Jesper Langgaard

AU - Reuber, J.

AU - Fröhlich, R.

AU - Hoppe, D.

PY - 2004/10/1

Y1 - 2004/10/1

N2 - Stereoselective addition of aldehydes 4 to metallated 1-(1-cycloalkenyl) methyl N,N-diisopropylcarbamates 1 gave cyclic homoaldol adducts 6. By applying the (-)-sparteine method, enantiomerically enriched products were obtained. These were oxidatively cyclized to diastereomerically pure ¿-lactones 8 via the ¿-lactol ethers 7. After deprotonation of ¿-lactones 8 with lithium hexamethyldisilazide, a further substitution was achieved. By trapping the lactone enolates 11 with ß-naphthylmethyl bromide, single diastereomers of ¿-lactones 12 were produced.

AB - Stereoselective addition of aldehydes 4 to metallated 1-(1-cycloalkenyl) methyl N,N-diisopropylcarbamates 1 gave cyclic homoaldol adducts 6. By applying the (-)-sparteine method, enantiomerically enriched products were obtained. These were oxidatively cyclized to diastereomerically pure ¿-lactones 8 via the ¿-lactol ethers 7. After deprotonation of ¿-lactones 8 with lithium hexamethyldisilazide, a further substitution was achieved. By trapping the lactone enolates 11 with ß-naphthylmethyl bromide, single diastereomers of ¿-lactones 12 were produced.

UR - http://www.scopus.com/inward/record.url?scp=5644250666&partnerID=8YFLogxK

U2 - 10.1055/s-2004-831170

DO - 10.1055/s-2004-831170

M3 - Journal article

AN - SCOPUS:5644250666

SN - 0039-7881

SP - 2303

EP - 2316

JO - Synthesis (Germany)

JF - Synthesis (Germany)

IS - 14

ER -