27312-92-1

Upstream product

• 2270-59-9 1-bromo-4-methylpent-3-ene 
• 603-35-0 triphenylphosphine 

Downstream Products

• 121362-23-0 β-acaridial 
• 1027898-42-5 {(1R,2R)-1-[Bis-(4-methoxy-phenyl)-phenyl-methoxymethyl]-2-chloro-1,5-dimethyl-hex-4-enyloxy}-triethyl-silane 
• 36602-32-1 (E)-β-ocimene 

Relevant academic research and scientific papers

Total Syntheses of the Cytotoxic Marine Natural Product, Aplysiapyranoid C

The first total syntheses of the cytotoxic marine natural product, aplysiapyranoid C, 1c, are reported. The Wittig reaction of 4-methyl-3-pentenyltriphenylphosphorane with the THP ether of hydroxy-acetone gave in 88% yield the Z-alkene 4 which was hydrolyzed to the alcohol 5 in 72% yield. Sharpless asymmetric epoxidation of 5 afforded the epoxy alcohol 6 in 91% yield and 81% ee. Opening of the epoxide of 6 with ammonium chloride in DMSO gave in 76% yield the chloro diol 7 which was converted to the primary TBS ether 8 in 95% yield. Opening of the epoxy alcohol 6 with HCl and Ti(OiPr)4 afforded the desired chloro diol 7 as the minor product along with the rearranged chloromethyl diol 9. This compound is presumably formed by opening of the protonated epoxide to give a butenyl cation which rearranges to the cyclopropylcarbinyl cation and is then trapped by chloride ion at the unsubstituted cyclopropyl carbon, regenerating the alkene. Cyclization of the TBS ether 8 with tetrabromocyclohexadienone (TBCO) afforded a mixture of all four possible cyclization products, the desired tetrahydropyrans 11a,b and the tetrahydrofurans 12a,b with the former being isolated in 70% yield. Hydrolysis of the TBS ether afforded the primary alcohols from which the desired isomer, 13, could be isolated (24% overall from 8). Swern oxidation furnished the aldehyde 14 which was subjected to the Takai chlorovinylation to give a mixture of aplysiapyranoid C 1c and the reduced product, dechloroaplysiapyranoid C 15. This dechlorination under these conditions is quite unusual. A second synthesis of aplysiapyranoid C avoided this problem. Selective protection of the more hindered tertiary alcohol of the chloro diol 7 afforded the primary alcohol 16 in which the tertiary alcohol was protected as the triethylsilyl ether. Swern oxidation, Takai reaction, and desilylation gave the dichloro alkenol 17 in 52% overall yield. In this case, only a small amount of the corresponding dechlorinated product was obtained. Final cyclization of 17 with TBCO afforded aplysiapyranoid C 1c as the major product in an isolated yield of 43%. Thus we have completed two total syntheses of aplysiapyranoid C 1c from the simple bromide 2 in eight or nine steps and good overall yield.

Synthetic Studies on the Natural Product Myrsinoic Acid F Reveal Biologically Active Analogues

The synthesis of the structure, 1, assigned to the anti-inflammatory natural product myrsinoic acid F is reported together with a means for preparing its Z-isomer 21. While neither of these compounds corresponds to the natural product, both of them are anti-inflammatory agents (as determined using a mouse ear edema assay) with congener 1 being notably more potent than the widely prescribed NSAID indometacin.

2(E)-(4-Methyl-3-pentenylidene)-butanedial, β-Acaridial: A New Type of Monoterpene from the Mold Mite Tyrophagus putrescentiae (Acarina, Acaridae)

The natural product chemistry of opisthonotal gland excretion was studied for the mold mite Tyrophagus putrescentiae.The secretion contained a new type of monoterpene dial, 2(E)-(4-methyl-3-pentenylidene)-butanedial (1), which we gave the trivial name β-a

7-oxabicyclo(2.2.1)heptane compounds useful in the treatment of inflammation

7-Oxabicyclo(2.2.1)heptane analogs are disclosed having the general formula STR1 wherein R1 is lower alkyl, alkenyl, substituted alkenyl or alkynyl; R2 is lower alkyl, alkenyl or alkynyl; A is --CH2 --CH=CH-- or a single bond; X is --CH2, --CH(CH3) or --C(CH3)2 ; n is an integer from 0 to 9, with the proviso that when A is a single bond, n is an integer from 1 to 9; including all stereoisomers. These new compounds have been found to be inhibitors of arachidonic acid cyclooxygenase and are therefore useful as antiinflammatory antipyretic and analgesic agents.