Hb175 facial solarium

All reagents were purchased from Sigma Aldrich or Alfa Aesar and were used without further purification. The UV light source was provided by a Philips HB175 Facial Solarium (UVA, 365 nm, P = 4 × 15 W). Reverse phase column chromatography was carried out on Fluka Ltd silica gel 100 C18-reversed phase, under a positive pressure of compressed air. Analytical TLC analysis was performed using Merck 60 RP-18 F₂₅₄S aluminium-supported thin layer chromatography sheets and visualised using ninhydrin. ¹H and ¹³C NMR spectra were recorded on a Bruker Avance 400 (400 MHz, 100 MHz, respectively) or Bruker Avance III (500 MHz, 125 MHz, respectively). ¹H and ¹³C spectra were assigned using 2D NMR experiments including COSY, HSQC and HMBC. Melting points were performed on a Kofler Hotstage microscope and are uncorrected; the crystallisation solvent is shown in parentheses. IR spectra were recorded using a Bruker Tensor 27 spectrometer. Elemental analyses were submitted to the Elemental Analysis Service, London Metropolitan University. Optical rotations were recorded at 20 °C at the sodium D line (589 nm). ESG was prepared as previously reported.^{3 (link)} Selected examples of synthetic procedures are included below. Further details are available in the ESI.†