Reaktion #53761

Reaktionsgleichung

methyl (3R)-3-[(2-bromo-1-oxooctyl)oxy]-tetradecanoate

tert-butyl magnesium chloride

→

(6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one

Ausbeute 97.0%

Lösungsmittel

THF

THF

tetrahydro-furan

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded in any sequence, it
2. 2
   Sonstigeover a one hour
3. 3
   Sonstigeto a 60° C.
4. 4
   Sonstigereaction vessel

Vorschrift

While the α-halo ester III and the reactive species generating reagent can be combined or added in any sequence, it has been found that when the reactive species generating reagent is a Grignard reagent a simultaneous addition of the α-halo ester III and the Grignard reagent is particularly preferred. For example, simultaneous addition of 13.6 mL solution of 30.7 mmol of methyl (3R)-3-[(2-bromo-1-oxooctyl)oxy]-tetradecanoate in tetrahydro-furan (THF) and 3 equivalents of tert-butyl magnesium chloride in 86 mL of THF over a one hour period to a 60° C. reaction vessel containing about 10 mL of THF solvent resulted in 97% yield (A.N., i.e., area normalized) of (6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one when the crude product was analyzed by a gas chromatography 1 hr after the complete addition of reagents.

Quelle