Metalated 2-Alkenyl- and 1,2-Alkadienyl 2-Tetrahydropyranyl Ethers : Versatile Building Blocks for Furan Syntheses
Me3CLi metalated LiOCH2C:CCH2OTHP (THP = tetrahydro-2-pyranyl) quant. to LiOCH2CLi:C:CHOTHP which was treated with MeOH, Me(CH2)5I, or PhCH2Cl to give LiOCH2CR:C:CHOTHP [I; R = H, (CH2)5Me, CH2Ph]. Treating I with Me3CLi gave LiOCH2CR:C:CLiOTHP [R = (CH2)5Me] which was alkylated to LiOCH2CR:C:CR1OTHP [II; R = (CH2)5Me, R1 = Me, CH2CH:CHMe]. I and II were hydrolyzed by dil. acid and cyclized to 39-67% furans III [R = (CH2)5Me, R1 = H, Me, CH2CH:CHMe; R = CH2Ph, R1 = H]. In the same way, LiOCHR2C.tplbond.CCH2OTHP [R2 = Ph, CH:CMe2, Me, Pr, (Z)-CMe:CHMe] and LiOCHR3C.tplbond.CCHMeOTHP [R3 = Pr, (CH2)5Me] were converted into 53-81% furans III (R = H, R1 = CH:CMe2, Ph), IV [R = Me, R1 = (CH2)4Me; R = Pr, R1 = Et; R = CMe:CMe2, R1 = Me], and V [R = [(CH2)5Me, R1 = H, R = Pr, R1 = Et, R2 = Me]. [on SciFinder (R)]
1979
18
875
876
CAN 92:110747 27-6 Heterocyclic Compounds (One Hetero Atom) Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz. Journal 0044-8249 written in German. 71887-84-8 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation of, with tert-butyllithium); 71887-86-0P; 71887-87-1P; 71887-88-2P; 71887-90-6P; 71887-91-7P; 71887-95-1P; 71887-96-2P; 71887-97-3P; 71887-98-4P; 71887-99-5P; 71901-96-7P; 71901-97-8P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. and hydrolysis and cyclization of, furan deriv. by); 71887-89-3P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and C-alkylation of); 71887-85-9P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and C-protonation and alkylation of); 5312-82-3P; 10504-11-7P; 17113-33-6P; 62495-31-2P; 71887-92-8P; 71887-93-9P; 71887-94-0P; 71888-00-1P; 71888-01-2P; 71888-02-3P; 71888-03-4P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 6089-04-9 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with butyllithium and formaldehyde); 50-00-0 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with propynyl tetrahydropyranyl ether and butyllithium)
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