Hetero-atom effects on kinetic acidities: the metalation of 1-methylcyclohexene and its 4-aza- and 4-oxa-analogs

Hexane suspensions of Me3SiCH2K or BuLi/Me3COK deprotonated 1-methylcyclohexene almost exclusively at the Me group. In contrast 1,4-dimethyl-1,2,3,6-tetrahydropyridine and 4-methyl-5,6-dihydro-2H-pyran preferentially underwent H/metal-exchange at the N-distant and oxygen-adjacent allylic methylene groups, resp. Strong amide bases converted 5,6-dihydro-2H-pyrans into (Z)-pentadienols. The mechanism of the latter ring-opening is discussed. [on SciFinder (R)]


Published in:
Chimia, 39, 7-8, 231-2
Year:
1985
Keywords:
Note:
CAN 105:24154
27-16
Heterocyclic Compounds (One Hetero Atom)
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
0009-4293
written in English.
97847-48-8P; 102861-48-3P Role: FORM (Formation, nonpreparative), PREP (Preparation) (formation of, by base-promoted ring cleavage of ethylmethyldihydropyran); 102861-47-2P Role: FORM (Formation, nonpreparative), PREP (Preparation) (formation of, by base-promoted ring cleavage of methyldihydropyran); 695-16-9 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation and reaction of, with electrophiles); 591-49-1 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation and reaction of, with hydrogen peroxide); 16302-35-5; 63500-68-5; 63500-69-6 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation and ring cleavage of); 16302-35-5 Role: RCT (Reactant), RACT (Reactant or reagent) (metalation, Wittig rearrangement, and reaction of, with electrophiles); 4845-04-9P; 19734-43-1P; 63500-69-6P; 102861-42-7P; 102861-43-8P; 102861-44-9P; 102861-45-0P; 102861-46-1P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of)
Laboratories:




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


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