“…The reactor was heated at 130°C for 18 h. After the reactor was cooled to rt and excess gas was relieved, the solution was transferred into a flask and then evaporated to dryness. The residue was chromatographed on a silica gel column eluting with hexane and ethyl acetate (v/v, 8:1 5,148.5,147.6,131.3,128.7,128.4,127.3,127.2,126.9,125.8,118.2,118.1,85.8,85.1,57.5,52.6,14.7,14.4;IRm (C@O) 1698 cm À1 ; HRMS for C 21 H 18 O 2 : Calc. 302.1307, obsd.…”