Tetrahydrofuran → Pyren-1(2H)-one

Participants

Reaction Steps

To the 7,24-bis-OSiMe3-protected 1″,2″-dihydro-3″-aldehyde (1″,2″-dihydro-Intermediate II, 30 mg) in THF (0.8 μL) at rt was added 1-methoxy-3-trimethylsilyloxy-butadiene (50 μL) followed by ZnCl2 (80 μL, 1M solution in Et2O) After 2 h at rt and 12 h at 0° C., bis-protected Diels-Alder adducts were obtained without workup by PTLC on silica gel (1×1000 μm plate) using 2/8 acetone/hexanes as eluant. The pure products (7 mg methoxy-substituted pyranone and 10 mg pyrenone) thus obtained were characterized by 1H NMR. Both products were deprotected separately as described previously (10 mg pyrenone yielded 9 mg deprotected product and 7 mg methoxypyranone yielded 6 mg deprotected product). The deprotected products were characterized by 1H NMR.

Provenance & Evidence