A STUDY OF THE OXYANION EFFECT IN REACTIONS OF 2-METHYL-2-PROPEN-1-OL

Article abstract of DOI:10.1016/S0040-4020(01)86746-6

Optimum conditions for the self reaction of the potassium alkoxide of 2-methyl-2-propen-1-ol to give 3,5,5,-trimethyltetrahydropyran-2-ol (7) have been developed.Evidence is presented to demonstrate that the key carbon carbon bond forming step in this reaction formally involves an unusual type of Ene reaction between 2-methylpropenal and the allylic alkoxide anion in which stepwise or highly asynchronous hydride transfer precedes carbon carbon bond formation.Under different reactions conditions the condensation of 2-methylpropenal with the potassium alkoxide of 2-methyl-2-propen-1-ol proceeds to give the bicyclic lactone, 6-endo-hydroxy-7-exo-(2-methyl allyloxymethyl)-3-oxa-1,5,7-trimethyl bicyclo<3,3,1>nonan-2-one (11), the crystal structure of which is reported.