Introduction of sulphenyl or halogen substituents at C-7 of ketone (1), followed by stereospecific reduction steps, provides a selective route either to the (6RS,7RS,9RS) or to the (6RS,7RS,9RS) isomers, (10) and (11), of 7-(1-hydroxyethyl)-8-oxo-1-aza-3-oxabicyclo[4.2.0]octane-2-spirocyclohexane.
在C-7
酮(的
硫基或卤素的取代基引入1),随后通过立体有择还原步骤,提供了一种选择性的路线或者到(6个RS,7个RS,9个RS)或所述(6个RS,7个RS,9 7-(1-羟乙基)-8-
氧代-1-
氮杂-3-
氧杂
双环[4.2.0]辛烷-2-螺
环己烷的RS)异构体(10)和(11)。