88986-87-2Relevant academic research and scientific papers
Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(-)-myrtenol nitrate
Bew, Sean P.,Hiatt-Gipson, Glyn D.,Mills, Graham P.,Reeves, Claire E.
, p. 1081 - 1095 (2016/07/06)
Here we report the chemoselective synthesis of several important, climate relevant isoprene nitrates using silver nitrate to mediate a 'halide for nitrate' substitution. Employing readily available starting materials, reagents and Horner-Wadsworth-Emmons chemistry the synthesis of easily separable, synthetically versatile 'key building blocks' (E)- and (Z)-3-methyl-4-chlorobut-2-en-1-ol as well as (E)- and (Z)-1-((2-methyl-4-bromobut-2-enyloxy)methyl)-4-methoxybenzene has been achieved using cheap, 'off the shelf' materials. Exploiting their reactivity we have studied their ability to undergo an 'allylic halide for allylic nitrate' substitution reaction which we demonstrate generates (E)- and (Z)-3-methyl-4-hydroxybut-2-enyl nitrate, and (E)- and (Z)-2-methyl-4-hydroxybut-2-enyl nitrates ('isoprene nitrates') in 66-80% overall yields. Using NOESY experiments the elucidation of the carbon-carbon double bond configuration within the purified isoprene nitrates has been established. Further exemplifying our 'halide for nitrate' substitution chemistry we outline the straightforward transformation of (1R,2S)-(-)-myrtenol bromide into the previously unknown monoterpene nitrate (1R,2S)-(-)-myrtenol nitrate.
Synthesis of 2-C-methylerythritols and 2-C-methylthreitols via enantiodivergent Sharpless dihydroxylation of trisubstituted olefins
Ghosh, Shibaji K.,Butler, Mark S.,Lear, Martin J.
supporting information; experimental part, p. 2706 - 2708 (2012/07/27)
The mevalonate-independent pathway (MIP) is an interesting avenue for antimicrobial lead discovery. Here, we present a unified enantioselective synthesis of all four stereoisomers of 2-C-methyltetrol. These are useful building blocks of many bioactive natural products, including 2-C-methylerythritol phosphate (MEP) of the MIP biosynthetic pathway.
An efficient method for the p-methoxybenzylation of hydroxy groups with 2-(4-methoxybenzyloxy)-3-nitropyridine
Nakano, Masakazu,Kikuchi, Wataru,Matsuo, Jun-Ichi,Mukaiyama, Teruaki
, p. 424 - 425 (2007/10/03)
2-(4-Methoxybenzyloxy)-3-nitropyridine (PMBONPy), easily prepared from 2-chloro-3-nitropyridine and p-methoxybenzyl (PMB) alcohol, reacts with various types of hydroxy groups in the presence of a catalytic amount of trimethylsilyl triflate (Me3SiOTf) to give the corresponding PMB ethers in high yields under mild conditions.
Synthesis of the C29-C44 portion of spongistatin 1 (altohyrtin A)
Wallace, Grier A.,Scott, Robert W.,Heathcock, Clayton H.
, p. 4145 - 4152 (2007/10/03)
Two synthetic approaches to the C29-C44 portion of spongistatin 1 (ahohyritin A) have been developed. The key step of the first approach relies on the Claisen rearrangement of glucal 18 to provide ester 20a. This intermediate was advanced to silyl enol ether 30, which was coupled under Mukaiyama aldol conditions with aldehyde 3. Cyclization of this aldol adduct completed our first synthesis of the C29-C44 portion of spongistatin 1, requiring 25 total steps and occurring in 2.4% yield over the longest linear sequence (21 steps). We have also developed a second-generation approach based on the C-glycosidation of glucal 43. Through equilibration of the corresponding C-glycosides 49a/b and 50a/b the desired C-glycoside (50a) was obtained in good yield. Aldol condensation of this ketone provided cyclization precursor 67, which undergoes acid-catalyzed ketalization to close the E-ring of the spongistatins. An oxidation/reduction protocol was employed to set the C37 stereocenter. Protection of the C37 carbonol and selective unmasking of the C44 carbonol completed our second generation synthesis. This approach requires 27 steps and occurred in 13-2% yield over the longest linear sequence (18 steps).
