(R)-4-(5-ethoxycarbonyl-3-phenoxymethyl-pyrazol-1-ylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester 、 (S)-6-hydroxymethyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one 、 (S)-2-phenoxymethyl-6-trimethylsilanyloxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one 生成 (R)-2-Phenoxymethyl-6-trimethylsilanyloxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one