5-((tert-butyldimethylsilyl)oxy)furan-3-yl pivalate 、
tert-butyl 4-oxopent-2-ynoate 以
四氢呋喃 为溶剂,
反应 1.0h,
以to give bicycle (9) (110 g, 236 mmol, yield taken after subsequent step) in >20:1 regioselectivity as a viscous burgundy oil的产率得到Tert-butyl 3-acetyl-4-((tert-butyldimethlsilyl)oxy)-6-(pivaloyloxy)-7-oxabicyclo[2.2.1]hepta-2,5-diene-2-carboxylate