Y‐Zeolite‐Catalyzed Cyclizations of Terpenols

Abstract

Depending on the metal doped and the activation temperature, Y-zeolites can catalyze a diversity of reactions of geraniol (1), linalool (2) and nerol (3). Compound 1 can be transformed to a-and/or gcyclogeraniol (4 and 5) highly efficiently.

Stereoselective Disposition of the Geminal Dimethyl Group in the Cyclization of Geranyl Acetate under Zeolite Confinement Conditions

“…In addition, geranylacetone ( 2 ) is selectively transformed into α‐ambrinol ( 2c ) by a tandem sequence involving a 1,5‐diene cyclization followed by a highly diastereoselective intramolecular carbonyl‐ene reaction of γ‐cyclogeranylacetone ( 2a ). Similar cyclization results were reported almost simultaneously by a Chinese group14 using zeolites NaY and FeY.…”

En route to terpene natural products utilizing supramolecular cyclase mimetics

“…Geraniol or geranyl acetate (7) produced cyclogeranyl derivatives 8 as main products employing either zeolites or chlorosulfuric acid. [20][21][22] Related head-to-tail cyclizations have also been observed with sesquiterpene substrates using the conditions reported for monoterpenes 20,22 or employing superacids. 23 Strong acids seem to favor protonation of the head olen in solution.…”

Selective Monocyclization of Epoxy Terpenoids Promoted by Zeolite NaY. A Short Biomimetic Synthesis of Elegansidiol and Farnesiferols B−D

“…Our belief was based on the fact that, recently, we and others had reported the efficient biomimetic cyclization of small acyclic terpenoids, such as geranyl derivatives, by adsorption within the confined environment of a zeolite. We found that zeolite NaY, a mildly acidic (containing both Lewis and Brønsted acidic sites) catalyst, promoted these cyclizations in surprisingly high yields and with good selectivities.…”