A regio- and stereocontrolled access to 2,4-dienols by amide/alcoholate-promoted ring-opening of dihydropyrans

Dihydropyrans I (R = R1 = H, R2 = H, Me, CH2CH2CH:CMe2; R = Me, CH2CHMe2, R1 = H, R2 = Me; R = R2 = H, R1 = CH:CMe2), when treated with LiN(CHMe2)2-KOCMe3, underwent smooth ring cleavage through b-elimination to give dienols (Z)-HOCHRCR1:CR2CH:CH2. Methylenetetrahydropyrans II (R3 = Me, CH2CHMe2) gave HOCHR3CH2C(CH:CH2):CH2, while II (R3 = H) gave (E)-HOCH2CH:CMeCH:CH2. Other cyclic or acyclic homoallylic ethers reacted similarly. [on SciFinder (R)]


Published in:
Tetrahedron Letters, 26, 8, 1035-8
Year:
1985
Keywords:
Note:
CAN 103:87461
23-7
Aliphatic Compounds
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
0040-4039
written in English.
123-38-6 Role: RCT (Reactant), RACT (Reactant or reagent) (cyclocondensation of, with methylbutenol); 763-32-6 Role: RCT (Reactant), RACT (Reactant or reagent) (cyclocondensation of, with propanal); 41649-14-3; 97847-50-2 Role: RCT (Reactant), RACT (Reactant or reagent) (lithiation and elimination reaction of); 3174-74-1; 4203-45-6; 16302-35-5; 36838-71-8; 55130-15-9; 55873-95-5; 59848-65-6; 59848-66-7; 97847-43-3; 97847-47-7 Role: RCT (Reactant), RACT (Reactant or reagent) (lithiation and ring cleavage of); 1572-08-3P; 10034-09-0P; 14314-21-7P; 19774-38-0P; 40930-20-9P; 59163-76-7P; 65442-32-2P; 71885-98-8P; 77192-27-9P; 87832-31-3P; 88888-64-6P; 97847-44-4P; 97847-45-5P; 97847-46-6P; 97847-48-8P; 97847-49-9P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 63500-68-5P; 63500-69-6P; 63500-70-9P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn., lithiation, and ring cleavage of)
Laboratories:




 Record created 2006-03-03, last modified 2018-01-27


Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)