The synthesis of several derivatives of 2H-pyran-3(6H)-ones and their Michael adducts is described. Phenylthio, benzenesulfonyl, p-acetylaminobenzenesulfonyl, and p-bromophenyl substituents are beneficial for activity against gram-positive bacteria. 2-[4-(Phenylthio)phenyl]-2-methyl-6-methoxy-2H-pyran-3(6H)-one (8a) showed a minimum inhibitory concentration of 1.56 micrograms/mL against Staphylococcus aureus ATCC 2593, and 2-[4-(phenylthio)phenyl]-2-methyl-6-[(p-nitrobenzoyl)oxy]-2H-pyran-3 (6H)-one (9) showed a minimum inhibitory concentration of 0.75 microgram/mL against Streptococcus sp. C203M. In general, derivatives of 6-hydroxy-2H-pyran-3(6H)-ones with substituents at C-2 and C-6 showed significant activity against gram-positive bacteria. More specifically, the bulkier the C-2 substituent, the greater the antibacterial activity. Michael adducts of thiols (13) showed activity, which may be due to a retro-Michael reaction. In conclusion, the alpha,beta-enone system is essential for the activity of 6-hydroxy-2H-pyran-3(6H)-ones, and the size and nature of substituents at C-2 are associated with antimicrobial activity.

中文翻译：

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2H-吡喃-3（6H）-一衍生物及相关化合物的合成及抗菌性能。

描述了2H-pyran-3（6H）-one的几种衍生物及其Michael加合物的合成。苯硫基，苯磺酰基，对乙酰氨基苯磺酰基和对溴苯基取代基对于抵抗革兰氏阳性细菌的活性是有益的。2- [4-（苯硫基）苯基] -2-甲基-6-甲氧基-2H-吡喃-3（6H）-一（8a）对金黄色葡萄球菌ATCC 2593和2的最低抑菌浓度为1.56微克/ mL -[4-（苯硫基）苯基] -2-甲基-6-[（对硝基苯甲酰基）氧基] -2H-吡喃-3（6H）-一（9）对链球菌的最低抑制浓度为0.75微克/ mL sp。C203M。通常，在C-2和C-6处带有取代基的6-羟基-2H-吡喃-3（6H）-one的衍生物显示出对革兰氏阳性细菌的显着活性。更具体地，C-2取代基越庞大，抗菌活性越大。硫醇的迈克尔加合物（13）表现出活性，这可能是由于麦克尔逆反应所致。总之，α，β-烯酮体系对于6-羟基-2H-吡喃-3（6H）-酮的活性是必不可少的，并且C-2处取代基的大小和性质与抗菌活性有关。