AMBERLYST-15-CATALYZED CYCLIZATION
79
2-Vinyl-2,6,6-trimethyl-3,4,5,6-tetrahydro-2H-pyran (2f). IR: nmax cmꢁ1
1
2929, 1381, 1367, 1347 and 1220. H NMR (400 MHz, CDCl3, Me4Si): dH 1.18
(6H, s), 1.19 (3H, s), 1.3–2.2 (6H, m), 4.95 (2H, m), 5.95 (1H, dd, J ¼ 18, 10.8).
HRMS: found 154.2509 (calc. for C10H18O: 154.2516), 137, 121, 109, 93 (100%),
95, 84, 79, 71, 66, 43.
2,2,6-Trimethyl-oxepane (2g). IR: nmax cmꢁ1 2920, 1470, 1384, 1164, 1089,
879, 772. NMR (400 MHz, CDCl3, and Me4Si): dH 0.85 (3 H, d, J ¼ 7.0 Hz), 1.2 (6 H,
s), 1.5–1.8 (6 H, m), 3.4 (2H, m). HRMS: found 142.2420 (calc. for C9H18O
142.2413), 127, 112, 97, 84, 70, 56, 42.
ACKNOWLEDGMENTS
We thank the Kelkar Education Trust and S. H. Kelkar Company for research
support and encouragement.
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