Ionization of 2-brexyl brosylate: an exo-like rate without symmetrical bridging

Non‐canonical Biosynthesis of the Brexane‐Type Bishomosesquiterpene Chlororaphen through Two Consecutive Methylation Steps in Pseudomonas chlororaphis O6 and Variovorax boronicumulans PHE5‐4

“…These data revealed a helical tricyclo[4.3.0.0 3.7 ]nonane skeleton comprised of two partially superimposed norbornyl units known as brexane (in reference to the bridge involving an exo‐norbornyl bond) [13] . Brexanes have previously been explored as models for non‐classical carbocations, [14–21] but have never been observed as natural products. The 5‐ethyl‐2‐methylene‐1,3,4,6,7‐pentamethylbrexane skeleton of chlororaphen ( 6 ) corresponds to an EIMS fragmentation pattern that shows characteristic fragment ions at m / z 150 for C 11 H 18 from neutral loss of C 6 H 10 , and m / z 122 for C 9 H 14 from neutral loss of C 8 H 14 (Figure 3a).…”

“…These data revealed a helical tricyclo[4.3.0.0 3.7 ]nonane skeleton comprised of two partially superimposed norbornyl units known as brexane (in reference to the bridge involving an exo-norbornyl bond). [13] Brexanes have previously been explored as models for nonclassical carbocations, [14][15][16][17][18][19][20][21] but have never been observed as natural products.…”