Heptane

The chemicals used for sample preparation were all of analytical grade, except as otherwise stated. The following were purchased from Cambridge Isotope Laboratories, (Andover, MA, USA): stable isotope labelled IS compound 13C5-proline, 2H4-succinic acid, 13C5, 15 N-glutamic acid, 1,2,3-13C3 myristic acid, 2H7-cholesterol and 13C4 disodium alpha-ketoglutarate. The following were purchased from Campro (Veenendaal, The Netherlands): 13C12-sucrose, 13C4-palmitic acid and 2H4-butanediamine. 2HCl and 13C6-glucose from Aldrich (Steinheim, Germany) and 2H6-salicylic acid from Icon (Summit, NJ, USA). Stock solutions of the IS were prepared either in purified and deionised water (Milli-Q, Millipore, Billerica, MA, USA) or in methanol (J.T.Baker, Deventer, Holland) at the same concentration, 0.5 μg/μl. Metyl stearate was purchased from Sigma (St. Louis, MO, USA). N-Metyl-N-trimethylsilyltriflouroacetamide (MSTFA) with 1% trimethylchlorosilane (TMCS) and pyridine (silylation grade) were purchased from Pierce Chemical Co, Dallas,TX, USA). Heptane was purchased from Fisher Scientific (Loughborough, UK).

Gelatin from bovine skin (gel strength 225 g; bloom, type B) was purchased from Sigma-Aldrich (Darmstadt, Germany), the liquid crystal 4-cyano-4′-pentylbiphenyl (5CB) was purchased from TCI Europe (Zwijndrecht, Belgium), and the ionic liquid [BMIM] [DCA] (≥98%) was purchased from IoLiTec (Heilbronn, Deutschland). The solvents dichloromethane and hexane were purchased from VWR (Radnor, United States), and ethanol (purity $\ge 99.8\%$ ) was purchased from Sigma-Aldrich. Acetonitrile (purity $\ge 99.9\%$ ), chloroform, diethyl ether (HPLC grade), diethyl acetate, heptane, methanol (HPLC grade), and toluene were supplied by Fisher Scientific (Hampton, VA, USA). Acetone (purity $\ge 99.5\%$ ) was purchased from Honeywell (Charlotte, NC, USA). Solvents were of analytical grade and used as received.

Gelatin from bovine skin (gel strength ≈225 g; Bloom, Type B), glutaraldehyde solution (50 wt % in water), fluorescein isothiocyanate isomer I, and sodium bicarbonate were purchased from Sigma-Aldrich. Dimethyl sulfoxide was obtained from Fisher Scientific. The LC 4-cyano-4′-pentylbiphenyl (5CB) was acquired from TCI Europe, and the IL [BMIM][DCA] (˃98%) was purchased from IoLiTec. The solvents dichloromethane and hexane were purchased from VWR, and ethanol (purity ≥99.8%) was purchased from Sigma-Aldrich. Acetonitrile (purity ≥99.9%), chloroform, diethyl ether (HPLC grade), ethyl acetate, heptane, methanol (HPLC grade), and toluene were supplied by Fisher Scientific. Acetone (purity ≥99.5%) was purchased from Honeywell, and isopropanol (purity ≥99.5%) from ROTH. Solvents were of analytical grade and used as received.

Isooctane, benzene, heptane, and methanol were purchased from Fisher Scientific Korea Ltd. (Seoul, Korea) or Junsei Chemical Ltd. (Tokyo, Japan). Standards of a 37-fatty acid methyl ester (FAME) mixture (CRM47885), pentadecanoic acid (C15:0, P6125), sulfuric acid (H₂SO₄), dimethyl sulfoxide, 2,2-dimethoxypropane (DMP), and dichloromethane were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA).

PEGDMA MW 1000 and MW 20 000 were purchased from Polysciences and were used as received. The ultraviolet (UV) photoinitiator, 2-hydroxy-1-[4-(hydroxyethoxy) phenyl]-2-methyl-1 propanone (I2959) and fibronectin were purchased from Sigma Aldrich. Methacrylate acid (MAA) was purchased from Fisher Scientific and was passed through a basic alumina column prior to use to remove inhibitor. Heptane was purchased from Fisher Scientific. 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), sulfo-N-hydroxysulfosuccinimide (sulfo-NHS), 2-(N-morpholino)ethanesulfonic acid (MES) Buffer, and 1X phosphate buffer saline (PBS) were purchased from Thermo Fisher Scientific.

Heptane, hexane, methanol, ethanol, and acetonitrile were the HPLC grade solvents obtained from Fisher Scientific (Fair Lawn, NJ, USA) and used as received. Acetic acid, triethylamine, and ammonium formate were purchased from Sigma-Aldrich (Millipore-Sigma, Burlington, MA, USA).
As outlined in Scheme 1, racemic analytes were prepared via short two and three-step sequences beginning with readily available propargylic derivatives XIII and XIV. In the case of the oxazole derivatives I-V, ene substrates were prepared through reaction of propargyl alcohol (XIII) with the appropriate nitrile derivative in the presence of HCl, affording the corresponding imidate XV in good-to-excellent yield [5 (link)]. Treatment of the imidates with CuI resulted in hydroamination of the alkyne and formation of the methylidene oxazoles XVI [5 (link)]. Exposure of XVI to either N-phenylmaleimide or ethyl glyoxylate delivered the corresponding ene adducts I-V in modest to good yields [24 ]. The thiazoline derivatives XVII were prepared in analogous fashion through a one-step thio acylation/hydroamination sequence [6 (link),7 (link)] and then subjected to ene reactions with N-phenylmaleimide and ethyl glyoxylate, which afforded the corresponding adducts in generally good yields.