222539-29-9

Synthesis of (R)-8-hydroxy-2,7-dimethyl-(4E,6E)-octadienyl β-D- glucopyranoside (1), a glycosidic precursor of marmelo oxides, the volatile components of quince fruit, Cydonia oblonga Mill., was achieved starting from (S)-3-hydroxy-2-methylpropanoate (5).

The application of fluorous mixture synthesis (FMS) for accessing natural products and their stereoisomers was validated by the total synthesis of all 16 stereoisomers of the pine sawfly sex pheromone. Four fluorous p-methoxybenzyl groups were used as tag

A convergent and modular synthesis has been devised to construct the eight diastereoisomers of deoxyfusapyrone (1). In this paper the synthesis of the complex polyene chain is reported as is its connection to the pyrone moiety that is in the middle of the

The synthesis of the C18-C31 subunit of orevactaene (1) in an enantioselective and convergent manner is reported. Four chiral centers in the structure (i.e., carbons 23, 25, 32, and 33) have unknown configuration; thus, a modular approach has been devised to link the two stereocenter-containing ends of the structure together via a trisubstituted olefin template to ultimately produce all possible diastereomers of the target. Keys to the success of this approach include (i) an efficient synthesis of four diastereomeric hydrophobic tails (C22-C29) of the molecule with two stereogenic centers at C23 and C25; (ii) the synthesis of three stereodefined trisubstituted olefins 37, 38, and 43 using palladium(0)-catalyzed hydrometalation and metallometalation; and (iii) the convergent assembly of the aforementioned sections by a 'one-pot' lithium/halogen exchange, boron/lithium exchange, borate ester saponification, and Suzuki cross-coupling followed by oxidative deprotection. The sequence provided the desired aldehydes 49 and 50 as single isomers in good yields. Compiled spectroscopic data from the literature and present work provides evidence that the relative configuration of the methyl groups in the side chain of orevactaene may be 1,3-syn, which will be confirmed when the total synthesis has been completed. These results have paved the way for a parallel synthesis approach to prepare all 16 possible stereoisomers of orevactaene so that the relative and absolute stereochemistry of this compound can be determined.

Both (2R,6R)- and (2S,6S)-isomers of 2,6-dimethylheptane-1,7-diol monotetrahydropyranyl ether (4) were synthesized, and converted into the enantiomers of anti-10,14-dimethyl-1-octadecene (1), anti-5,9-dimethyloctadecane (2) and anti-5,9-dimethylheptadecane (3), the sex pheromone components of the apple leafminer (Lyonetia prunifoliella).

A convenient partial synthesis of the lactone (+)-10 is reported starting from the readily available methyl (S)-(+)-3-hydroxy-2-methylpropanoate (+)-1. Furthermore, an efficient three step route to the optically active saturated isoprene unit (-)-13 in high yield starting from the lactone (+)-10 is reported for the first time.

The structure of the sex pheromone produced by the male sandfly Lutzomyia longipalpis, from the Lapinha Cave (Minas Gerais State) region of Brazil, previously proposed tentatively as the novel homosesquiterpene 9- methylgermacrene-B, is confirmed and the