Cohalogenation of limonene, carvomenthene and related unsaturated monoterpenic alcohols

Abstract

A coalogenação de (R)-limoneno e (R)-carvomenteno com I 2 /H 2 O/Cu(OAc) 2 ·H 2 O em dioxano aquoso seguida por tratamento em meio básico produz estereoespecificamente os transepóxidos correspondentes. Já essa mesma metodologia de coalogenação aplicada a álcoois monoterpênicos insaturados estruturalmente relacionados produz derivados do pinol [a partir de (5R)-cis-carveol e (S)-α-terpineol] ou então iodoidrinas [a partir de (S)-álcool perílico e (5R)-Cohalogenation of (R)-limonene and (R)-carvomenthene with I 2 /H 2 O/Cu(OAc) 2 ·H 2 O in aqueous dioxane followed by base treatment produced stereospecifically the corresponding trans-epoxides. Same methodology of cohalogenation applied to related monoterpenic unsaturated alcohols produced pinol derivatives [from (5R)-cis-carveol and (S)-α-terpineol] or iodohydrins [from (S)-perillyl alcohol and (5R)-trans-carveol].

Trichloroisocyanuric Acid: An Alternate Green Route for the Transformation of Alkenes into Epoxides

“…The purity of the products was > 90 -99 % (by HRGC) and they were characterized by Disappointing results were obtained when the methodology was applied to limonene as it was produced trans-1,2-epoxylimonene (ca. 45 % by HRGC, confirmed by coinjection with an authentic sample 15 ) along with unreacted substrate and several other minor products (none of them limonene epoxides) Scheme 3.…”

Studies on the Cohalogenation of Limonene With N-Halosuccinimides and N-Halosaccharins in Water. A Chemo-and Stereoseletive Preparation of (1s, 2r, 4r)-1,2-Epoxylimonene

“…After the end of the reaction (15), the solvent was evaporated under reduced pressure and the haloidrins were reacted with excess Na 2 C0 3 in aqueous etanol for 24 h. The crude products were analyzed by HRGC by co-injection with authentic samples (9,16) and the results are summarized in Scheme-2 and Table-1.…”

“…dioxane produced stereospecifically the iodohydrin 3c(9). Halohydrins 3 produced trans-1,2-epoxylimonene when treated with aqueous bases (8-10) Scheme-1.…”

A Centennial Methodology for the Preparation of Heterocyclic Compounds: The Intramolecular Coiodination of Alkenes with Internal Oxygenated Nucleophiles

“…These pinol derivatives of unambiguously stereochemistry [49] were obtained as sole products within a total stereochemical control. Furthermore, we noted that the relative position of the OH group was crucial for the intramolecular reaction as trans-carveol and perillyl alcohol afforded the corresponding iodohydrins (24) and (25) through an intermolecular reaction [48].…”

“…Recently, we [48] reported the preparation of the pinol derivatives (22) and (23) by the intermolecular coiodination of cis-carveol and α-terpineol respectively. These pinol derivatives of unambiguously stereochemistry [49] were obtained as sole products within a total stereochemical control.…”