In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
The synthesis of an new photochromical compound,1,3,3 trimethyl 6′ (1 piperidinyl) spiro[2h indole 2,3′ [3H]pyridobenzoxazine (SP3),and an improved way for the synthesis of 6 hydroxyquinoline were descrided.The abso...The synthesis of an new photochromical compound,1,3,3 trimethyl 6′ (1 piperidinyl) spiro[2h indole 2,3′ [3H]pyridobenzoxazine (SP3),and an improved way for the synthesis of 6 hydroxyquinoline were descrided.The absorption spectrum of the colored metastable form SP3 shows prominent absorption peak at 560nm at 60℃?展开更多
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘The synthesis of an new photochromical compound,1,3,3 trimethyl 6′ (1 piperidinyl) spiro[2h indole 2,3′ [3H]pyridobenzoxazine (SP3),and an improved way for the synthesis of 6 hydroxyquinoline were descrided.The absorption spectrum of the colored metastable form SP3 shows prominent absorption peak at 560nm at 60℃?
