A Simple, Readily Accessible, and Effective Apparatus for the ­Photoisomerization of cis-Cyclooctenes to trans-Cyclooctenes

Abstract

A simple, cost effective, and readily accessible apparatus for the photoisomerization of cis-cyclooctenes to trans-cyclooctenes is described. Utilizing only FEP tubing, aluminum vent pipe, a household germicidal lamp, and a flash chromatography system, trans-cyclooctenes can be prepared in good yield.

Key words

trans-cyclooctene - photochemistry - bioconjugation - click chemistry - flow chemistry

• References and Notes

• 1 Blackman ML, Royzen M, Fox JM. J. Am. Chem. Soc. 2008; 130: 13518
• 2 Agard NJ, Prescher JA, Bertozzi CR. J. Am. Chem. Soc. 2004; 126: 15046
• 3 Hoyle CE, Bowman CN. Angew. Chem. Int. Ed. 2010; 49: 1540
• 4 Darko A, Wallace S, Dmitrenko O, Machovina MM, Mehl RA, Chin JW, Fox JM. Chem. Sci. 2014; 5: 3770
• 5a Rossin R, Renart VerkerkP, van den Bosch SM, Vulders RC, Verel I, Lub J, Robillard MS. Angew. Chem. Int. Ed. 2010; 122: 3447
• 5b Zeglis BM, Sevak KK, Reiner T, Mohindra P, Carlin SD, Zanzonico P, Weissleder R, Lewis JS. J. Nucl. Med. 2013; 54: 1389
• 5c Houghton JL, Zeglis BM, Abdel-Atti D, Sawada R, Scholz WW, Lewis JS. J. Nucl. Med. 2016; 57: 453
• 5d Stéen EJ. L, Jørgensen JT, Johann K, Nørregaard K, Sohr B, Svatunek D, Birke A, Shalgunov V, Edem PE, Rossin R. ACS Nano 2019; 14: 568
• 5e Evans HL, Nguyen Q.-D, Carroll LS, Kaliszczak M, Twyman FJ, Spivey AC, Aboagye EO. Chem. Commun. 2014; 50: 9557
• 6 Ji X, Pan Z, Yu B, De La Cruz LK, Zheng Y, Ke B, Wang B. Chem. Soc. Rev. 2019; 48: 1077
• 7a Lang K, Davis L, Wallace S, Mahesh M, Cox DJ, Blackman ML, Fox JM, Chin JW. J. Am. Chem. Soc. 2012; 134: 10317
• 7b Nikić I, Estrada GironaG, Kang JH, Paci G, Mikhaleva S, Koehler C, Shymanska NV, Ventura Santos C, Spitz D, Lemke EA. Angew. Chem. Int. Ed. 2016; 55: 16172
• 7c Peng T, Hang HC. J. Am. Chem. Soc. 2016; 138: 14423
• 8a Yang KS, Budin G, Reiner T, Vinegoni C, Weissleder R. Angew. Chem. Int. Ed. 2012; 124: 6702
• 8b Zlitni A, Janzen N, Foster FS, Valliant JF. Angew. Chem. Int. Ed. 2014; 126: 6577
• 9a Jendralla H. Angew. Chem., Int. Ed. Engl. 1980; 19: 1032
• 9b Shea KJ, Kim JS. J. Am. Chem. Soc. 1992; 114: 4846
• 9c Reese CB, Shaw A. J. Am. Chem. Soc. 1970; 92: 2566
• 9d Braddock DC, Cansell G, Hermitage SA, White AJ. Tetrahedron: Asymmetry 2004; 15: 3123
• 9e Whitham G, Wright M. J. Chem. Soc. C 1971; 886
• 9f Whitham G, Wright M. J. Chem. Soc. C 1971; 891
• 9g Ziegler K, Wilms H. Justus Liebigs Ann. Chem. 1950; 567: 1
• 9h Cope AC, Pike RA, Spencer CF. J. Am. Chem. Soc. 1953; 75: 3212
• 9i Hines JN, Peagram MJ, Thomas EJ, Whitham GH. J. Chem. Soc., Perkin Trans. 1 1973; 2332
• 9j Corey E, Shulman JI. Tetrahedron Lett. 1968; 9: 3655
• 9k Vedejs E, Snoble KA, Fuchs PL. J. Org. Chem. 1973; 38: 1178
• 10 Royzen M, Yap GP, Fox JM. J. Am. Chem. Soc. 2008; 130: 3760
• 11a Svatunek D, Denk C, Rosecker V, Sohr B, Hametner C, Allmaier G, Fröhlich J, Mikula H. Monatsh. Chem. 2016; 147: 579
• 11b Billaud EM, Shahbazali E, Ahamed M, Cleeren F, Noël T, Koole M, Verbruggen A, Hessel V, Bormans G. Chem. Sci. 2017; 8: 1251
• 11c Fang Y, Zhang H, Huang Z, Scinto SL, Yang JC, am Ende CW, Dmitrenko O, Johnson DS, Fox JM. Chem. Sci. 2018; 9: 1953
• 11d Pigga JE, Fox JM. Isr. J. Chem. 2020; 60: 207
• 12 Ruivo E, Elvas F, Adhikari K, Vangestel C, Van Haesendonck G, Lemière F, Staelens S, Stroobants S, Van der Veken P, Wyffels L. ACS Omega 2020; 5: 4449
• 13 {(2s,3aR,9aS,E)-3a,4,5,8,9,9a-Hexahydrocyclo-octa[d][1,3]dioxol-2-yl}methanol (2): Typical ProcedureA round-bottomed flask was charged with {(2s,3aR,9aS,Z)-3a,4,5,8,9,9a-hexahydrocycloocta[d][1,3]dioxol-2-yl}methanol (12:1 mixture of syn and anti diastereomers, 368 mg, 2.00 mmol), methyl benzoate (545 mg, 4 mmol), and a 1:1 mixture of diethyl ether and heptane (80 mL), then capped with a septum through which two small holes were bored to accommodate the insertion of 1/8′′ OD tubing. Solvent inlet line ‘A’ from an Interchim flash chromatography system was inserted into one of the holes in the septum containing the cis-cyclooctene mixture. The ‘waste’ line from the Interchim chromatography system was fitted with a 1/4-28 flangeless fluidic transfer fitting and connected to one end of the photoreactor’s ETFE tubing via a fluidic transfer union. The other end of the photoreactor’s tubing was passed through the remaining hole in the septum of the round-bottomed flask containing the cis-cyclooctene mixture, thus creating a closed loop. A 12 g cartridge containing 4.4 g of 10% w/w AgNO₃ impregnated silica gel (top) and approximately 7 g of unmodified silica gel (bottom) was equilibrated with a 1:1 mixture of diethyl ether and heptane, then fitted to the Interchim system. A 25 W germicidal lamp was placed in the center of the photoreactor, and a blast shield covered in aluminum foil was placed in front of the lamp and photoreactor. The Interchim flash chromatography system was programmed to pump a gradient consisting of 100% solvent A at a rate of 100 mL/min for 3–8 h and to send all fractions to waste. The reaction was initiated by switching on the germicidal lamp and Interchim pump. After 8 h, solvent inlet line A was removed from the reaction mixture and submerged in 50 mL of 1:1 diethyl ether and heptane, and the mixture was pumped through the system and eluted into a waste container. The flash cartridge was removed from the Interchim system, and its contents were emptied into a 250 mL Erlenmeyer flask. DCM (100 mL) and ammonium hydroxide (100 mL) were added to the Erlenmeyer flask and stirred vigorously for 10 min. The mixture was filtered over a pad of Celite, and the phases were separated. The aqueous phase was washed with DCM (2 × 50 mL), and the combined organics were dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The crude residue was subjected to flash chromatography on silica (0–20% EtOAc in heptane), and after pooling and concentrating the appropriate fractions, the title compound was obtained as a colorless oil (12:1 mixture of syn and anti diastereomers; run 1: 229 mg, 62%; run 2: 222 mg, 60%). NMR data attributable to syn isomer: ¹H NMR (500 MHz, benzene-d ₆): δ = 5.32–5.23 (m, 1 H) 5.19–5.11 (m, 1 H) 4.77 (t, J = 3.4 Hz, 1 H) 3.69–3.58 (m, 3 H) 3.53–3.45 (m, 1 H) 2.14–2.00 (m, 2 H) 1.97–1.91 (m, 1 H) 1.86–1.75 (m, 2 H) 1.72 (br d, J = 14.7 Hz, 1 H) 1.53–1.42 (m, 2 H) 1.39–1.29 (m, 1 H) ppm.