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The structurally intriguing terpenes pallambins C and D have been assembled in only 11 steps from a cheap commodity chemical: furfuryl alcohol. This synthesis, which features a redox-economic approach free of protecting-group manipulations, assembles all four-ring systems via a sequential cyclization strategy. Of these fourring constructing operations, two are classical (Robinson annulation and Mukaiyama aldol) and two are newly devised. During the course of this work a method for the difunctionalization of enol ethers was developed, and the scope of this transformation was explored. [ABSTRACT FROM AUTHOR]

3-Carene, α-pinene, and limonene α-(dimethylamino)oximes were converted to glycidyl ethers at the oxime hydroxyl. The compounds obtained were involved in the reactions with amines, imidazole, as well as with anions of these dimethylamino oximes. The glycidyl ether epoxide ring opening by amines under microwave irradiation conditions proceeds considerably faster than upon convection heating. [ABSTRACT FROM AUTHOR]

A total synthesis of (±)-cis-5-hydroxycalamenene 1 has been achieved from tetralone 5, which in turn was prepared from 5-methoxy-α-tetralone 3. Grignard reaction of compound 5 with isopropylmagnesium chloride, followed by dehydration and aromatization, provided the substituted naphthalene 7 whose conversion to (±)-cis-5-hydroxycalamenene 1 was accomplished by demethylation, formylation, and hydrogenation. [ABSTRACT FROM AUTHOR]

A general preparation method of the all-(E)-polyprenols 12 has been developed from readily available geranyl sulfone by the chain-extension process utilizing the C5 unit 5 and the chain-termination process utilizing the C5 unit 10 together with the chemoselective reductive desulfonylation. The polyprenols 12 were converted to compounds 3 containing two consecutive prenyl sulfone moieties at the tail end, which underwent the controlled electrophilic cyclization only at the carbon-carbon double bonds that were remote from the flat and rigid benzenesulfonyl groups. [ABSTRACT FROM AUTHOR]

The review discusses recent advances in the field of acid-catalyzed intra- and intermolecular transformations of pinane terpenoids and their oxygen-containing derivatives. [ABSTRACT FROM AUTHOR]

Abstract: Turpentine, an important source of terpenes, is composed mainly of α- and β-pinene. It is possible to pyrolyze β-pinene to form myrcene, which is used as an intermediate for the production of various terpenic alcohols and chemical aromas, as well as vitamins A and E. In the current work we develop a theoretical equilibrium model of the main synthesis reactions that have been described in the literature plus postulated decomposition reactions. The model predicts that 93.5% yields of myrcene from β-pinene would be possible whereas the highest reported yield is 85%. In order to investigate the less than theoretical yields, we investigated the decomposition of myrcene experimentally. The various degradation products that appeared were consistent with a degradation mechanism involving breakage next to conjugated double bonds, producing an alkyl radical. Decomposition of myrcene by this route would form 1,3-butadiene (C4H6) and 4-methyl-1,3-pentadiene (C6H10), which then further decompose into various other products. These results contribute to a better understanding of the production of myrcene by pyrolysis of β-pinene and could form the basis for optimization of product yields. [Copyright &y& Elsevier]

The first total synthesis of an (E)-cladiellin diterpene, (-)-cladiella-6,11-diene-3-ol (1), was accomplished featuring an intramolecular amide enolate alkylation-intramolecular Diels-Alder strategy. In addition, a highly stereo-, regio-, and chemoselective synthetic strategy for other members of the cladiellin diterpenes such as (+)-polyanthellin A (2), (-)-cladiell-11-ene-3,6,7-triol (3), and (-)-deacetoxyalcyonin acetate (4) was developed utilizing the synthetic (E)-cladiellin 1 as a common intermediate by taking advantage of the unique chemical properties of its C(6)-(E)-oxatricyclic skeleton. [ABSTRACT FROM AUTHOR]

Abstract: Starting with larixol, syntheses of furan and 1,4-enedial labdane-type diterpenes are presented, which has enabled a preparation of hedychenone (20% yield). [Copyright &y& Elsevier]

The article reports on the synthesis of tenuifolin through intramolecular nicholas reaction.

Review: 102 refs. [ABSTRACT FROM AUTHOR]

isolation, structure elucidation and cytotoxicity of ent-abierubesins A-E (I)-(IV) and new ent-kauranoids, hubeirubesins A (V) and B (VI) [ABSTRACT FROM AUTHOR]

isolation and structure elucidation [ABSTRACT FROM AUTHOR]

The key step of this synthesis of the title compounds (respectively their enantiomers) is an organocatalyzed asymmetric [4 + 3] cycloaddition yielding key intermediate (V). [ABSTRACT FROM AUTHOR]