Rearrangements in Dihydroresorcinol Derivatives. IV. Claisen Rearrangement of 3-Allyloxy-2-cyclohexen-1-ones
1971 年 19 巻 3 号 p. 571-575
詳細
1971 年 19 巻 3 号 p. 571-575
Heating of 3-allyloxy-2-cyclohexen-1-ones (IIa, b, c) caused a Claisen rearrangement and simultaneous cyclization to give 2-methyl-4-oxo-2, 3, 4, 5, 6, 7-hexahydrobenzofurans (IIIa, b, c) in 75, 70 and 78% yields, respectively. Under similar conditions, 3-allyloxy-2-methyl-2-cyclohexen-1-one (VI) gave 2-allyl-2-methylcyclohexane-1, 3-dione (VII) in 81% yield, and 3-prenyloxy-2-cyclohexen-1-one (VIII) gave 2, 2, 3-trimethyl-4-oxo-2, 3, 4, 5, 6, 7-hexahydrobenzofuran (IX) in 95% yield. The reaction mechanisms were also discussed.
