Direct Conversion of an Alcohol Tetrahydropyranyl Ether to a Bromide, Chloride, Methyl Ether, Nitrile or Trifluoroacetate

Stereoisomers and analogs of 14-methyl-1-octadecene, sex pheromone of peach leafminer moth,Lyonetia clerkella, L.

“…The condensation itself was conducted to maximize the cis-olefin dihydropyran, H+; 2. pyridinium chlorochromate, sodium acetate; 3. butyllithium (~ ylid), procedure for cis (Sonnet, 1974); 4. triphenylphosphine dibromide; 5. lithium diisopropylamide; 6. olefin inversion via bisepoxides (Sonnet and 0liver, 1976). generated by using hexamethylphosphoric triamide as an additive (Sonnet, 1974). Completion of the pheromone synthesis involved conversion of the tetrahydropyranyl ether of the (R)-and (S)-alkene 5 to a bromide 6 with triphenylphosphine dibromide .…”

Clay Supported Cerium(IV) Reagents for Oxidative Deprotection of Tetrahydropyranyl Ethers under Non-Aqueous Conditions

“…Tetrahydropyranyl ethers are useful as protecting groups and important building blocks for the synthesis of primary alcohols [1], allylic alcohols [2], and alkyl halides [3]. More recently, the tetrahydropyranylation process (THP ether synthesis) has been performed under environmentally friendly conditions with concomitant minimum puri®cation requirement.…”

“…More recently, the tetrahydropyranylation process (THP ether synthesis) has been performed under environmentally friendly conditions with concomitant minimum puri®cation requirement. The methods employed include the use of heterogeneous catalysts such as montmorillonite K-10 [3], sulfonated charcoal [4], H-Y zeolite [5], zinc chloride in alumina [6], envirocat-EPZG [7], natural kaolinite clay [8], and zeolites HSZ [9]. However, the latter has been claimed to effect protection as well as deprotection of hydroxy compounds.…”

Palladium-Catalyzed Oligocyclizations of Some 2-Bromotetradec-1-ene-7,13-diynes Under Heck Reaction Conditions

“…[37] The produced compound 51 is then coupled, at −78 o C, with lithiated 2-(3-butynyloxy)tetrahydro-2H-pyran 52, prepared from PPTS-catalyzed reaction of 2,3-dihydropyran with 3-butyn-1-ol which was obtained from acetylene and ethylene oxide, [38] in THF and HMPA to give 53 in a 48% yield. Subsequently, the OTHP group of 53 is converted into its corresponding bromide [39] 54 which is then attached to sodium malonate, generated by treating diethyl malonate with sodium hydride, to furnish 55 in a 63% yield. The produced diethyl 2-(10'-phenyl-3',9'decadiynyl)malonate 55 is then treated with sodium hydride in DME and coupled with 2,3-dibromopropene to afford the target precursor 48 in a 44% yield.…”

“…+ −COOCH 3 ], 269(46) [ M + −CH 3 OH−COOCH 3 ], 241(39), 209(20), 159(30), 115 (72), 74 (79), 59 (100), 45 (64), 43 (27).− C 20 H 24 O 6 (360.4) calcd for: C 66.65,…”