Publication
Consecutive treatment of endo-butenylpotassium or endo-1-(tetrahydropyranyloxy)-exo-butenyllithium with FB(OMe)2 and pentanal at -75 Deg affords an erythro- and, threo-adduct, resp., which on hydrolysis and oxidn. lead to cis- and, trans-5-butyl-4-methyl-tetrahydro-2-furanone (4-butyl-3-methyl-4-butanolide), (I), the so-called quercus or oak lactones, resp. [on SciFinder (R)]
Xile Hu, Srikrishna Bera, Deyun Qian