抄録
Diketene reacted with diazoacetophenone (Ia) to give two isomeric spiro compounds, 2-(trans-2-benzoyl-1-hydroxycyclopropane)-acetic acid β-lactone (IIa) and 2-(cis-2-benzoyl-1-hydroxycyclopropane)-acetic acid β-lacton.e (IIa'). Similarly, p-methoxy-α-diazoacetophenone (Ib) was transformed to 2-[trans-2-(p-methoxybenzoyl)-1-hydroxycyclopropane]-acetic acid β-lactone (IIb) and 2-[cis-2-(p-methoxybenzoy1)-1-hydroxycyclopropane]-ace tic acid β-lactone (IIb'). Reaction of diketene with ethyl diazoacetate (Ic) gave furanone derivatives, 2, 5-dihydro-2-ethoxycarbonyl-3-methylfuran-5-one (VII) and 2, 5-dihydro-4-ethoxycarbonyl-methylfuran-2-one (VIII), together with 2-(trans-2-ethoxycarbony1-1-hydroxycyclo-propane) acetic acid β-lactone (IIc).
