(R/S)-3-benzyl-2-t-butyl-4-imidazolidinone hydrochloride   、                                                                                      diacetonide of 2-keto-(L)-gulonate                                                                                                                                                                                                                                                                                                          生成                                                 (3aR,4aR,7aS,7bS)-2,2,6,6-Tetramethyl-dihydro-furo[2,3-d;4,5-d']bis[1,3]dioxole-3a-carboxylic acid; compound with (S)-3-benzyl-2-tert-butyl-imidazolidin-4-one