“…All the pentane washings and extracts were combined, washed with water, dried (Na2S04), and concentrated. The residual white solid was sublimed at 80°( 1 mm) to give 9.0 g (41% from the crude diene) of solid, mp 94-96°( lit.7 mp 90-92), that was 99.3% endo.endo diene and 0.7% endo.endo monoene (gc analysis on a 25% SE-30 on Chromosorb W colunn26): ir (CC14) 3.21 (w), 3.30 (m), 3.41 (s), 3.52 (m), 6.39 (w), 6.90 (m), 7.49 (s), 7.88 (w), 8.00 (s), 8.11 (w), 8.20 (w), 8.85 (m), 9.12, (w), 9.71 (w), 10.13 (w), 10.35 (w), 10.99 (s), 11.31 (a), 11.45 (s), 14.00 (vs), 14.50 µ (w).…”