Synthesis of two pyranoquinolinones. What is the structure of cherimoline ?

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

“…The use of dehydroamino acids such as olefin 16 [36] in Heck reactions [37–42] is also of interest, since these coupling products are useful intermediates for the synthesis of non-proteinogenic amino acids [43]. To our delight, the Heck coupling of syn - 4a and 16 could be efficiently achieved employing Jeffery´s conditions [44]. When the coupling was performed using palladium(II) acetate, solid NaHCO 3 and tetra- n -butylammonium bromide (TBAB) at 130 °C [37–38 42] the desired β-1,2-oxazinyl-substituted dehydroamino acid derivative syn - 17 was obtained in 69% yield.…”

A Chiral Pool Strategy for the Synthesis of Enantiopure Hydroxymethyl‐Substituted Pyridine Derivatives

“…Heck coupling between the pyridyl nonaflate ent-45 and ethyl acrylate under Jeffery conditions afforded 51 in 66 % yield. [21] Reductions of aryl triflates or nonaflates to the corresponding unsubstituted arenes under homogeneous conditions are well established. [22] We were pleased to find that these conditions can also be applied to the reduction of the pyrid-4-yl nonaflate 45, affording the pyridine derivative 52, unsubstituted at C-4, in excellent yield.…”

Thermolysis of N‐Aryl Enaminoimine Hydrochloride Derivatives: A Short and General Method for the Synthesis of Pyranoquinolin‐3‐one and Pyranoacridin‐3‐one Derivatives

“…Chromenoquinoline derivatives have been reported to act as human progesterone receptor and have been used therapeutically. Although coming across the literature, we found a gradual increase on the studies towards the synthesis of pyridocoumarin derivatives since 1999 and in the last decade, a large number of synthesis of such compounds have been reported by various groups especially by Majumdar et al . .…”