Functionalized 1‐Alkoxy‐1,3‐dienes: Their Preparation and Applications in Synthetic Organic Chemistry

Abstract

The reaction of various α,β‐unsaturated acetals with two equivalents of the Schlosser reagent LIC‐KOR [equimolar mixture of BuLi (LIC), and tBuOK (KOR)] gives 1‐metalated (1E)‐1‐alkoxy‐1,3‐dienes. These products can be transformed into trienic derivatives that are apt to participate in intramolecular Diels–Alder (IMDA) cycloaddition reactions, and can also be transformed into bifunctional (γ‐halo‐α‐carbonyl) reagents. Moreover, the metalated dienes can be readily functionalized with suitable electrophiles to afford products that have been found to be useful reagents for the Stille and Suzuki cross‐coupling reactions or arylated according to the conditions of the Heck process. Other significant syntheses of dienic and polyenic structures are reported along with some of their applications in organic synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

A Survey of Recent Synthetic Applications of 2,3-Dideoxy-Hex-2-enopyranosides

“…The hetero Diels-Alder reaction (HDA) has been amply used in the de novo synthesis of hexoses, and in many those instances 2,3-unsaturated derivatives have been key intermediates in these protocols [27,28,29]. Pioneering work by Danishefsky’s group had shown that hexoses could be accessed by Lewis acid-catalyzed HDA reaction of alkylated siloxy dienes with aldehydes via the intermediacy of labile 3- O -silyl-2,3-unsaturated glycoside adducts [30,31].…”

Thioether-functionalized trifluoromethyl-alkynes, 1,3-dienes and allenes: divergent synthesis from reaction of 2-trifluoromethyl-1,3-conjugated enynes with sulfur nucleophiles

“…As a consequence, substantial efforts have been made over the years by synthetic organic chemists in order to design and develop methods allowing efficient access to a variety of functionalized allenes, 4 alkynes 5 and 1,3-dienes. 6 Meanwhile, the widespread use of uorinated, especially triuoromethylated, compounds in pharmaceutical chemistry, agrochemistry 7 and materials science 8 has attracted considerable interest in development of various synthetic methodologies for synthesis of these tri-uoromethylated species. 9 In this context, special attention has naturally been brought to triuoromethyl-allene, 10 alkyne 11 and 1,3-diene 12 building blocks and how to access them.…”

Stereoselective Synthesis of Functionalized 1,3‐Dienes in Water

“…[10][11][12][13] Conjugated dienes represent one group of broadly occurring and important organic compounds. Their importance stems mainly from their flexibility in organic transformations, [14][15][16][17] and the extensive amount of the 1,3-diene substructure in a vast array of natural products of biological and medicinal interest. [18][19][20][21][22][23][24][25] The development of methods for the efficient, stereoselective, and practical synthesis of conjugated dienes has attracted much interest from synthetic organic chemists.…”