2 -Tosyloxymethylcyclanones: Ring size dependence of fragmentation versus intramolecular alkylation

Syntheses around the Transglycosylation Step in Peptidoglycan Biosynthesis

“…Originally it was planned to open the seven-membered ring of 169a with an alkoxide by a Grob fragmentation. It turned out, however, that the Grob fragmentation of 2-tosyloxycycloalkanones is restricted to five-membered rings whereas in larger ring systems C- and O-alkylation processes prevail . On the other hand, a sulfenylating β-ketoester cleavage of 169b furnished 172 via 171 (77%) (Scheme ).…”

“…It turned out, however, that the Grob fragmentation of 2-tosyloxycycloalkanones is restricted to five-membered rings whereas in larger ring systems C-and O-alkylation processes prevail. 182 On the other is assembled from a C 10 and a C 15 precursor as indicated in Figure 16. 163,185 The structures of moenocinol (145) and diumycinol (182d) are closely related, but still the adaption of the moenocinol route to the diumycinol synthesis was far from straightforward especially for the Kocienski approach (Scheme 29).…”

Intramolecular [2+2] Cycloaddition of Homoallylketenes to Bicyclo[2.1.1]hexan-5-ones

“…17,18) These compounds have been prepared by photolysis of γ,δ-unsaturated chromium-carbene complexes, 10) intramolecular alkylation of 2-tosyloxymethylcyclopentanones 19,20) and β′-silyloxy enol triflate, 21) or oxidative rearrangement of bicyclo[2.2.0]hexan-2-ol.…”

Examining the Scope of Deriving β-Aryl Enones from Enol Silanes as Ketone Equivalents via Pd(II)-Mediated Sequential Dehydrosilylation and Arylation

“…The arylboronic acid starting materials 2a – 2z and aryl halide starting materials 9a – 9k are available commercially. All silyl enol ether starting materials ( 1a , 6a , 6b , 6c , 6d , 6e , 6f , and 10a ) have been known in the literature and were prepared as per the literature protocols.…”